University of Waterloo Weather Station blog

Temperature Drop

2012-01-18T08:11:00.002-05:00

In the 3 hours between 4:45 pm to 7:45 pm on Tuesday, the temperature fell from 8.2°C down to -2.8°C.

2011 Summary

2012-01-12T22:00:00.000-05:00

The biggest weather story of the year in the region was that it was a very wet year. With 1146.4 mm of total precipitation it was the 4th wettest year since records began in 1914 (the 3 wettest years were 1985-1186.4 mm, 1940-1174.9 mm, and 2008-1159.5 mm).

The only months that were significantly below average were June and July while all the spring and fall months were all very much above average. This included the wettest April ever, the fifth wettest May, and the third wettest October. The single day with the highest precipitation was November 29th with 52.1 mm.

In total there was 165.5 cm of snow during the calendar year of 2011, which is just a little more than the average of 159.5 cm. The biggest one day snowfall of 26 cm happened on March 24th, this was the snowiest day in 3 years.

Overall the temperature for 2011 was a full degree above average putting it around the 14th warmest off all time. However, it is worth looking at how the temperature varied between the first and second half of the year. From January to June the temperature was half a degree colder than average while for July and December it was about 2.5 degrees warmer than average. Each month in the second half of the year it was more than 1.5 degrees warmer than average, making it the warmest July to December period ever seen in the region.

On January 23rd, the high temperature during the day of -16.6°C was the coldest daytime high since January 15th of 2004. The 35.7°C on July 21st was the highest temperature seen since August 8th, 2001 when it was 36.5°C. Note that this high temperature was actually recorded at the Waterloo-Wellington Airport as the UW weather station unfortunately had been vandalized and was not accurately reading temperature at this time.

On the morning of October 23rd at 4:45 am the temperature went below zero for the first time since the spring and thus the frost free season went from May 1st to October 22nd which is a total of 175 days. This was the longest frost free season since records began in the region in 1915, just beating out 1941 when there was a stretch of 174 days above zero.

Click on the image below to see the temperature chart:

Click on the image below to see the precipitation chart:

December 2011 Summary

2012-01-03T22:28:00.000-05:00

December was much warmer and wetter than average

Yet another warm month, in fact there was only 1 day (the 10th) that was colder than average, making it just like November at 3.6 degrees warmer than average overall. However, as we have seen many above average Decembers in the past 10 years, we only have to go back to 2006 to find a warmer one.

One interesting story was the lack of cold temperatures, the minimum temperature during the month was -9.9°C. Only back in 1974 was there a December when the minimum temperature was higher (-7.8°C).

It was a consistently wet month with lots of days with some precipitation for a total of 94.0 mm compared to an average of 71.1 mm. We saw 17.5 cm of snow during the month which is less than half of the average of 38.5 cm.

Summary for December 2011:
Maximum Temperature 11.9°C
Minimum Temperature -9.9°C
Average Daily High Temperature 2.7°C (Long term average -0.4°C)
Average Daily Low Temperature -3.4°C (Long term average -7.5°C)
Total Precipitation 94.0 mm (Long term average 71.1 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Fall 2011 Summary

2011-12-23T17:20:00.001-05:00

A very warm fall that was also the wettest on record

The fall was over 2.5 degrees warmer than average, the heat was very consistent throughout the entire season except for a relatively cool week at the end of October. But even for that week it was only 3 or 4 degrees colder than average compared too many days that were more than 5 degrees warmer throughout the fall. However, as we have seen many warm falls in the recent past, we only have to go back to 2001 to find one that was hotter.

It was a very wet fall with 349.2 mm of total precipitation compared to the average of only 218.1 mm. This was the highest fall precipitation I could find, just beating out 1955 which had 339.5 mm.

There was only 5 cm of snow recorded this fall which is much less than the average of 30 cm. The fall of 1998 was the last time we have seen anything like this, as that year we only had 2 cm.

Summary for Fall 2011:
Maximum Temperature 26.7 °C
Minimum Temperature -9.7 °C
Average Daily High Temperature 10.7 °C (Long term average 8.3 °C)
Average Daily Low Temperature 2.5 °C (Long term average -0.5 °C)
Total Precipitation 349.2 mm (Long term average 218.1 mm)

(Long term averages based on 1970-2000 data for the Waterloo Wellington Airport)

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November 2011 Summary

2011-12-06T22:32:00.001-05:00

The 5th warmest November on record that was also wetter than average

It was another warm month at an incredible 3.6 degrees higher than average. You have to go back to October of 2007 to find a month that was this much above average. As well, it was the warmest November since 2001 and the 5th warmest since records began in the region (the warmest was 1931 at 4.3 degrees above average).

Up until the last couple of days of the month it was looking like a dry month, however an amazing 51 mm on the 29th put us in the above average range. The final total was 106.6 mm compared to an average of 82.3 mm.

There has now been 1047.6 mm of precipitation this year, well over the average of 932.9 mm and the third most ever recorded for the end of November. However, we will have to get over 140 mm in December to beat the all time annual record.

Summary for November 2011:
Maximum Temperature 17.7°C
Minimum Temperature -4.6°C
Average Daily High Temperature 9.8°C (Long term average 5.6°C)
Average Daily Low Temperature 1.6°C (Long term average -1.6°C)
Total Precipitation 106.6 mm (Long term average 82.3 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Longest frost free season ever seen

2011-10-24T00:09:00.002-04:00

On the morning of October 23rd at 4:45 am the temperature went below zero for the first time since the spring. It stayed below zero for almost 4 hours with the lowest temperature being -0.9°C.

The bigger news is that by my calculations the frost free season went from May 1st to October 22nd this year which is a total of 175 days. This is the longest frost free season I have been able to find since records began in the region in 1915. This year just beat out 1941 when they had a stretch of 174 days above zero.

For full disclosure I just want to mention that there isn't enough data for 1937 and 1938 to be included in the analysis.

Wettest day in over a year

2011-10-20T22:12:00.001-04:00

The 51.6 mm of rain in the 24 hours between 8 am on the 19th and 20th was the single wettest day we have had since July 23rd, 2010 when we had 62.5 mm.

September 2011 Summary

2011-10-06T16:25:00.000-04:00

Another hot month with average precipitation

With an average temperature that was 1.8 degrees above average, September was the third hotter than average month in a row. But it certainly wasn't consistent warm as the month was a battle between the cold arctic air masses and hotter air from the south. As a result we saw some drastic temperature changes such as a high of 30.5 C on the third and then a high of only 15.5 C two days later.

The precipitation for September was within the average range (95.3 mm compared to an average of 87.5 mm) even though there were 17 days with some measured precipitation, which is more than the average of 12. There were a couple of days with over 20 mm (the 19th and 27th) while the rest of it was was spread over many days with a bit of precipitation here and there.

The total precipitation at the end of September is 799.3 mm, which is still above the average of 680.7 mm for the end of the month.

Summary for September 2011:
Maximum Temperature 30.5°C
Minimum Temperature 3.5°C
Average Daily High Temperature 20.8°C (Long term average 20.0°C)
Average Daily Low Temperature 11.1°C (Long term average 8.3°C)
Total Precipitation 95.3 mm (Long term average 87.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

Summer 2011 Summary

2011-09-27T23:01:00.001-04:00

A dry and hot Summer

The hottest July in over 50 years followed by a warm August and September resulted in a summer that was one and half degrees higher than average. The 35.7°C on July 21st was the highest temperature we had seen in over 10 years.

Although the last half the summer was more or less average for precipitation it didn't make up for the very dry start to the summer that included the 7th driest July seen in the region. The total precipitation was 208.9 mm compared to an average of 274.0 mm.

This year's summer poll ended with 49% in the great catergory, 25% good, 14% OK, 5% bad, 4% total washout. Although this summer was different than the last ones the results always seem to be same no matter what the weather.

Summary for Summer 2011:
Maximum Temperature 35.7°C
Minimum Temperature 3.5°C
Average Daily High Temperature 25.5°C (Long term average 24.2°C)
Average Daily Low Temperature 14.1°C (Long term average 12.2°C)
Total Precipitation 208.9 mm (Long term average 274.0 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

Summer 2011 poll

2011-09-20T10:23:00.000-04:00

Let's see what everybody thought of this year's warm and dry summer.

The poll is located at the top of the UW weather station blog.

August 2011 Summary

2011-09-17T13:04:00.001-04:00

Another hot month with average precipitation

Another hot month coming in at 1.5 degrees warmer than average (the last time we had a colder than average one was back in March). The warmth was pretty consistent with lots of days where the highs were over 24°C but it never got over 30°C.

It was a pretty typical August in terms of precipitation, we got 79.7 mm which is within the average range for the month. There were a couple of big days when we were hit by typical August convective storms like the 31.4 mm on the 9th or the 17.9 mm on the 14th. After two dry months I think everyone's lawns and gardens will agree that this month made it a lot easier to survive.

The total precipitation for the year of 704.0 mm is still above the average for the end of August (596.0 mm).

Summary for August 2011:
Maximum Temperature 29.3°C
Minimum Temperature 11.3°C
Average Daily High Temperature 25.8°C (Long term average 24.7°C)
Average Daily Low Temperature 14.6°C (Long term average 12.6°C)
Total Precipitation 79.7 mm (Long term average 87.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

Cold tonight

2011-09-15T21:56:00.002-04:00

With a forecast low of 1, we might see the lowest temperature since early May overnight.

PS Hopefully the August summary will be available soon, it is being worked on.

July 2011 Summary

2011-08-01T16:57:00.004-04:00

**Note that as a result of an incident of vandalism at the UW weather station this month, the temperature used for this summary is based on data from the Waterloo-Wellington Airport**

The hottest July in over 50 years that was also very dry

Do I really have to tell anyone that it was hot this month? I guess the question was how hot it was historically. First off, it was over 2 degrees above average overall for the month with 11 days above 30 and an average daytime high of 29.4°C. I had to go back to 1955 to find a hotter July (which had a scorching daily average high of 32.2°C) and overall the month was tied for the 6th warmest that has ever been recorded in the area.

The 35.7°C on the 21st was the highest temperature we have seen since August 8th, 2001 when it was 36.5°C.

Going along with the hot weather was the lack of rain, up until the last couple of days of the month it looked like it might be the second driest ever recorded (it would have been hard to beat the paltry 1.8 mm recorded in 1916). However, a couple of storms right at the end of July got us up to 22.3 mm and as there will a lot of months around with around 20 mm, this year ended up as the 7th driest in the region since records began in 1914.

This dry month means that the total for the year (624.3 mm) is creeping slowly closer to the average (509.0 mm). It was the second wettest first 6 months of the year, but now it is only the 9th wettest first 7 months of the year.

Summary for July 2011:
Maximum Temperature 35.7°C
Minimum Temperature 6.9°C
Average Daily High Temperature 29.4°C (Long term average 26.0°C)
Average Daily Low Temperature 14.9°C (Long term average 13.8°C)
Total Precipitation 23.2 mm (Long term average 92.9 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

Very dry July

2011-07-27T22:21:00.002-04:00

Although we are scheduled to get some rain tonight and over the next few days it still looks like it may be one of the driest July every recorded in the area.

As of the 27th we have only had about 3.5 mm for the month, this is more than the incredibly dry July of 1916 when we only had 1.8 mm. To get second we have to have less than the 19.8 mm seen in 1919.

Weather Station Damaged

2011-07-26T09:09:00.004-04:00

Now that all the reports have been filed I can reveal that the reason the weather station has been giving us strange readings is that the station was vandalized during the evening of July 16th. The fenced off area containing the station was entered and main tower was pulled down:

We were lucky that the battery had enough power to keep the station going for the days when the solar panel was facing the ground and not charging.

It was very bad timing as during the week when we had the hottest temperatures in the past many years we were not able to get an accurate reading. This was because the temperature sensor was on its side and thus was getting hit with direct solar radiation after about noon. This caused the temperature to spike up much higher than it would have been "in the shade".

Here is the reason that the wind speed was zero:

The good news is that the station is pretty much back up, except for some quick fixes to the anemometers which will have to be replaced eventually.

Let's hope this is the one and only time I'll have to deliver news like this.

Equipment Problems

2011-07-19T22:52:00.000-04:00

As many people have noticed the temperature sensor is giving unrealistic readings during these days of very high temperatures.

We are working at trying to fix the problem.

June 2011 Summary

2011-07-03T12:17:00.001-04:00

Average temperatures for June and the first dry month of the year

Nothing too spectacular about the temperature in June, a few hot days at the beginning and a few cool days after that made for overall temperature that was just 0.3 degrees warmer than what we would expect putting it within the average range.

For the first time this year it was a drier than average month. Although it wasn’t drier by much as we had 60.4 mm and the average range starts at 64 mm. There was only one really wet day of the month, the 22nd when 28.2 mm fell, and there was a dry stretch from the 9th to the 20th.

Even with the relatively dry month, we still had 602.0 mm for the first half of the year which is well above the average of 415.0 mm. This is the second wettest first half of the year in the area since records began back in 1914. Only in 1947 was it wetter when 624.8 mm was recorded from January to June.

Summary for June 2011:
Maximum Temperature 32.0°C
Minimum Temperature 5.6°C
Average Daily High Temperature 23.2°C (Long term average 23.6°C)
Average Daily Low Temperature 12.2°C (Long term average 11.3°C)
Total Precipitation 60.4 mm (Long term average 80.0 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Spring 2011 Summary

2011-06-25T19:15:00.001-04:00

A very wet Spring with average temperatures

Apart from a cold start to the Spring it was actually pretty close to average for most of the season. The overall temperature was only slightly (0.2 degrees) lower than average. However, just looking at the daytime highs it was about a full degree less than average which is the coldest since 2003.

It was a very wet Spring with 338.2 mm of precipitation compared to the average of 219.5 mm. But this is not a record as we had 342.2 mm back in 1997 (that year saw over 100 mm during the first three weeks of June).

Summary for Spring 2011:
Maximum Temperature 32.0 °C
Minimum Temperature -17.5 °C
Average Daily High Temperature 14.9 °C (Long term average 15.9 °C)
Average Daily Low Temperature 5.0 °C (Long term average 4.4 °C)
Total Precipitation 338.2 mm (Long term average 219.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Quite an hour

2011-06-22T22:52:00.002-04:00

Between 9:15 and 10:15 pm on Wednesday, June 22 the temperature dropped 6.5 degrees and we got 21 mm of precipitation.

We are number one!

2011-06-18T15:25:00.005-04:00

From my friend Rob Kuhn:

At 3 pm on Saturday, June 18th, Kitchener-Waterloo was the warmest place in Canada at 28.0°C

May 2011 Summary

2011-06-01T22:14:00.001-04:00

The fifth wettest May on record, above average overall temperature, and the wettest ever start to the year

First off, how about that warm May! Hard to believe I know, but the daily low temperatures were a whopping 2.9 degrees above average for the month, this more than offset the daily highs that were 0.7 degrees below average. This means it was a little more than 1 degree above average overall for the month.

But of course people are going to remember the 4th when the high was only 7.0°C (the coldest daytime high in May since May 3rd, 2005) and the 16th when it only got up to 8.3°C.

One reason for the warmer than average nights was the amount of cloud cover we had during the month and the 17 days with some precipitation compared to an average of only 12, leading to...

The fifth wettest May since records began in the area at 150.3 mm, this actually ties us with May of 2000, but not close to the record back in 1956 when we had 202.2 mm. Just like April the first half of the month was very dry and it was the second half that put us well above average.

With the total precipitation for the year at 541.6 mm, not only is it well above the average (337.7) but it also way above the record which was 488.5 mm back in 1943.

Looking back now, it looks like April 30th will be the last frost day of the spring which is the earliest last frost date since 1999 when it was April 29th.

Summary for May 2011:
Maximum Temperature 31.1°C
Minimum Temperature 1.6°C
Average Daily High Temperature 18.2°C (Long term average 18.9°C)
Average Daily Low Temperature 9.4°C (Long term average 6.6°C)
Total Precipitation 150.3 mm (Long term average 75.7 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Shot of rain on Victoria Day

2011-05-25T16:59:00.002-04:00

On the Monday of the Victoria Day weekend between 6:30 and 6:45 pm we got 14.5 mm of rain.

It is not a record for 15 minute precipitation at the University of Waterloo Weather Station (that was last year on July 23rd with 18.1 mm), but it very well could be the highest for this year.

Victoria Day Weekends

2011-05-20T15:16:00.003-04:00

It seems that a lot of people think that Victoria Day weekend is always a particularly bad weather weekend. I have even written a blog entry on the subject here:

http://uwweatherstation.blogspot.com/2008/05/what-does-queen-victoria-have-against.html

This time let's look at precipitation, first off on average it rains about 1/3 of the days of May. So we would expect that on average it should rain one of the days of a 3 day long weekend. Over the past 12 years the breakdown of days with rain is as follows: 0 - 15%, 1 - 55%, 2-15%, 3-15%. I'm not sure of the actual probability distribution of such a series, but it seems pretty well what we would expect. It is also hard to make many conclusions with such a small sample.

Also interesting is that compared to other weekends (Sat, Sun, Mon) in May there is actually a better chance for 1 day or less of rain during the Victoria Day weekend. Or put another way there has been a greater chance for 2 or more days of rain during the other weekends of the month in the past 12 years.

And an update on temperatures during the Victoria Day holiday weekend, looking back at the last 12 of them (ie. the time the UW weather station has been around), it is true that about two-thirds have been colder than average. Random chance suggests we should be closer to 50/50. The forecast for this weekend looks like it might be the warmest in quite some time.

As I said in the last post about this topic, it is always the Victoria Day weekends that are really cold or wet that people seem to remember. Hopefully everyone can enjoy this weekend no matter what the weather.

Hottest day so far this year

2011-05-13T17:14:00.002-04:00

When it got up to 26.4°C on Friday it was the hottest it has been so far this year. But that looks to be the last of the warm temperatures until the middle of next week.

April 2011 Summary

2011-05-01T13:27:00.002-04:00

The wettest April ever recorded

It may be surprising to some, but it worked out to be an average month for temperature. Overall it was actually 0.1 degrees above average, however as often happens the daytime highs were half a degree below average while the night time lows were about half a degree above. As people will naturally tend to notice the high temperature of the day, the feedback I got from people was that they were expecting it to be a colder than average month.

Although we had a stretch of 8 days where it didn’t go above 10°C, this was offset by a couple of warm days at the beginning of the month (including the 10th when the UW weather station contest was decided – congratulations to Janie Simpson on winning) and a few more warm days near the end.

Another thing that might have put people in a bad mood about the weather was the amount of precipitation. It turns out that the month of April was the wettest since records began in the area in 1914 with 136.5 mm coming down, this just barely beat 1921 when there was 135.9 mm.

Even more shocking is that on the 15th the total for the month was actually a bit below average at only 29.2 mm. But then storm after storm seemed to hit us with four days in the last half of April that recorded more than 15 mm, propelling us to the record breaking total.

Another wet month means that the amount of precipitation that we have seen for the year (391.4 mm) is very much above average for the end of April (264.4 mm). This is now the second wettest first 4 months of the year, just barely behind 1954 when we had 401.3 mm at this point.

The final total for the snowfall season of 2010/2011 was 177 cm compared to the average of 159.5 cm, it came down to the wire with the last real storm of the season on March 23/24 putting us above the average.

Summary for April 2011:
Maximum Temperature 22.3°C
Minimum Temperature -3.6°C
Average Daily High Temperature 10.9°C (Long term average 11.4°C)
Average Daily Low Temperature 1.3°C (Long term average 0.6°C)
Total Precipitation 136.5 mm (Long term average 76.9 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Final numbers on the 2010-2011 snowfall season

2011-04-25T14:26:00.005-04:00

Well I don't want to jinx it, but I think we can finally call an end to the 2010-2011 snowfall season.

The final total was 177 cm compared to the average of 159.5 cm, it came down to the wire as the last real storm of the season on March 23/24 was what put us above the average.

From the graph (see below) you can see why I called it a "back end loaded" snowfall season. We were well below average until late January and then the switch got turned and we got storm after storm until mid-March.

The reason for this was that a zone of high pressure set up over Quebec during the fall and stayed around until late January. This meant that the jet stream was pushed further south and thus most of the storms were also deflected south of the Great Lakes. This pattern broke down in February and we returned to a more typical La Nina winter pattern with the jet stream coming over the Great Lakes. As storms are often carried along the jet stream it meant a lot more precipitation for us.

This pattern has continued on with what has been a pretty wet spring so far (and more rain in the forecast).

I also want to give a big thanks to my snow measurement volunteers: Melinda, Eric, and Jayson who helped gather the data during this year's snowfall season!

2011 UW weather station contest ends!

2011-04-10T15:45:00.002-04:00

Wow! I don't know if it has ever gone over 20 that fast before, it was only 11C out 2 hours before it went over 20C.

This year's winner is:

Janie Simpson

who correctly chose a time of 3:30 pm on April 10th as the first time the temperature at the UW weather station would go above 20C.

In second place we have:

Annarita Superina

Thanks to all 907 people who entered the contest, we hope you had fun with it and will enter again next year.

Once again we would like to thank The Waterloo Store who sponsored this year's prizes.

As well as taking home some cool prizes, the winners will also become members of the Waterloo Weather Station Contest Hall of Fame.

Could the 2011 contest end this weekend?

2011-04-07T13:17:00.001-04:00

The first above 20 degree temperatures are forecasted for this weekend.

March 2011 summary

2011-04-03T20:56:00.001-04:00

A cold March that was the wettest in almost 35 years

It was looking like an average month for temperature, but a very cold and clear last week put us 1.3 degrees below average. On some of these very cold days, the high temperature did not go above the average low temperature for the day.

The big story of the month was the 136.6 mm of total precipitation, this was almost twice the average of 70.6 mm and the wettest March since 1976 when we had 148.3 mm. There were two days with over 25 mm and three days in a row with over 15 mm. What
made it an even more astonishing total was that the last week of the month was dry.

With the biggest one day snowfall (26 cm) in three years happening on the 24th, it is not surprising that the month’s total snowfall of 50 cm was twice as much as the average of 24 cm.

This wet month put the amount of precipitation that we have seen for the year (254.8
mm), very much above average for the end of March (187.6 mm).

Summary for March 2011:
Maximum Temperature 13.6°C
Minimum Temperature -17.5°C
Average Daily High Temperature 2.4°C (Long term average 3.5°C)
Average Daily Low Temperature -7.1°C (Long term average -5.6°C)
Total Precipitation 136.6 mm (Long term average 70.6 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Spring 2011 snowstorm

2011-03-23T19:46:00.001-04:00

We had a total of 26 cm from the storm on March 23rd.

This is the highest single day snowfall since March 9, 2007.

The total snowfall this season of 175 cm is now above the average of 160 cm.

If you are seeing this on Wednesday night you might want to get to shoveling as there is a very wet layer under the snow. Once that layer freezes it looks like it won't melt until late next week.

Winter 2010/2011 summary

2011-03-21T17:57:00.002-04:00

A winter that was a bit colder and wetter than average

Overall the temperature was 0.6 degrees colder than average this winter, making it the coldest since 2005, but still within the average range. I think one reason it didn’t feel like a very cold winter was that it was never really cold for more than a few days in a row and the rest of the time it was just a few degrees below average. We also didn’t really see a mid-winter thaw, as between January 1st and February 13th it only went above zero for a single day.

For most of the winter the precipitation was very low, it wasn’t until late February that some very wet days put us back into the average range. The total precipitation was 220.4 mm compared to the average of 184.5 mm. This is almost double last year’s total of 113.2 mm, but not as much as the two years before that.

As always, it is hard to separate the snow during just the winter as opposed to the entire snowfall season. But, for just the winter we saw about 116 cm of snow compared to the average of 103 cm. However, it was really the 74 cm that came down in February that put us over the top.

Summary for Winter 2010/2011:
Maximum Temperature 13.6°C
Minimum Temperature -28.8°C
Average Daily High Temperature -1.8°C (Long term average -1.4°C)
Average Daily Low Temperature -10.6°C (Long term average -9.8°C)
Total Precipitation 220.4 mm (Long term average 184.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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February 2011 summary

2011-03-06T17:23:00.001-05:00

A month where both the temperature and precipitation were just within the average range

There were lots of dramatic temperature swings during the month with 20+ degree differences between the high and lows for a day commonplace. Although the temperature danced above and below average, overall the month was 0.7 degrees colder. However it is still considered an average month for temperature as it was within the average range.

The first week of the month had lots of precipitation and then it was then pretty dry until some rain on the last day. However, even though the total precipitation was 63.4 mm compared to the average of 51.3 mm, it was still (just barely) within the average range.

For the year so far, the amount of precipitation that we have seen (118.3 mm) is very close to the average at this time (115.7 mm).

It really has been a back-end loaded winter this year for snow as between October 1st and January 31st we had 71 cm of snow, but in February alone we had 56 cm. This is close to double to average snow in February of 30.6 cm.

Summary for February 2011:
Maximum Temperature 9.3°C
Minimum Temperature -23.4°C
Average Daily High Temperature -2.1°C (Long term average -1.9°C)
Average Daily Low Temperature -11.7°C (Long term average -10.5°C)
Total Precipitation 63.4 mm (Long term average 51.3 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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The 2011 Weather Station contest has started!

2011-02-24T12:04:00.000-05:00

It is that time of year again, time to put in your guess as to when the temperature will first go above 20.

Get all the details and enter the contest here.

Finally above zero

2011-02-18T17:00:00.001-05:00

When the temperature when above zero on February 13th it broke a streak of 42 days of below zero temperatures.

Warmest day since the new year

2011-02-17T09:53:00.001-05:00

If the forecasted high of 8°C comes to pass today, it would be the warmest day since January 1st.

Last cold day for a while?

2011-02-11T12:54:00.002-05:00

There is definitely a change coming, after Friday where the low dipped to -23.4°C in the morning, it looks like the temperature is going to slowly going to go up and up. It might not go down again till sometime on Sunday (maybe even Sunday evening).

And it's not just the short term that sees higher temperatures, with some forecasted highs of 6 in middle of next week.

After that, the medium range forecasts have it staying either at or a bit above average into mid-March. Thus I'll be bold and predict that today is going to be the coldest day we see until the fall.

January 2011 Summary

2011-02-03T18:17:00.001-05:00

The second colder than average month in a row with average precipitation

Unlike December, where we didn’t see any really cold temperatures, we had four days where it went below -20°C at night. This combined with many days that were a few degrees colder than average, put us as a little more than 2 degrees below average for the month. This was the first time since mid-2009 when we have had 2 below average months in a row.

On the 23rd, the high temperature during the day of -16.6°C was the coldest daytime high since January 15th of 2004 when it only got up to -17.8°C.

The month started out wet with lots of rain on the first, but it calmed down after that and the 54.8 mm of total precipitation was within the average range for the month.

The 42 cm of snow that came down during January was very close to the long term average of 43.5 cm. The largest single day was the 9.5 cm that fell during the 11th.

Summary for January 2011:
Maximum Temperature 10.1°C
Minimum Temperature -28.8 °C
Average Daily High Temperature -4.8 °C (Long term average -3.1 °C)
Average Daily Low Temperature -13.6°C (Long term average -11.1 °C)
Total Precipitation 54.8 mm (Long term average 64.4 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Groundhog Day storm final total

2011-02-03T11:57:00.003-05:00

In the end we got 16.5 cm of snow at the UW weather station in total over the two days of the Groundhog Day storm. Not quite as much as forecasted as it seemed that most of the heavy snow went to the south hitting the Hamilton region.

As forecasted the storm also lost a lot of its power after hitting Chicago and didn't produce the snow amounts here as it did there.

Stories from the storm

2011-02-01T19:21:00.001-05:00

I'm interested in hearing your stories about this storm, leave a comment with your experiences so far.

Groundhog Day storm of 2011

2011-02-01T19:14:00.002-05:00

So once the snow starts on Tuesday night it doesn't look like it will stop until very late Wednesday or even Thursday. Although the heaviest part will probably be around sunrise, it now looks like we might get hit by a wrap around arm of the storm during the afternoon which might add another 10 cm to whatever already have at that point.

I'm interested in hearing about people's predictions and stories about the storm.

So on this post I encourage you to leave a comment saying how much total snow we will recieve between Tuesday night and Wednesday evening, ie. what will be the sum of the readings from Wednesday and Thursday morning at the UW weather station website.

I'll have another post where you can post any stories about the storm.

Temperature Change

2011-01-28T08:29:00.000-05:00

At 7:45 am on Monday, January 24th it was -28.2°C and 24 hours later at 7:45 am on Tuesday, January 25th it was -3.1°C.

In some places in the world they don't see that kind of temperature difference during the year.

A very cold day forecasted on Sunday

2011-01-21T14:46:00.001-05:00

Environment Canada is forecasting a high of only -17 C on Sunday. If this were to happen it would be the coldest high temperature for any day since January 19th, 1994 when the high was a very frigid -21.3 C.

Cold start to the year

2011-01-20T18:08:00.002-05:00

So far the first 20 days of the year have been about a degree colder than average, continuing the trend we saw in December.

This could mean will see the first two colder than average months in a row since the middle of 2009.

Storm snow total

2011-01-12T16:55:00.003-05:00

We had about 12 cm of snow from Tuesday afternoon until Wednesday morning during the big storm that came across our area.

2010 Summary

2011-01-03T10:22:00.002-05:00

The big weather story for the year in the region were the consistent warm temperatures that lead to 2010 coming in as the 5th warmest year ever at 1.4 degrees above average. Eleven of the 12 months were higher than average with December being the only colder than average month.

The year didn’t start out spectacularly warm with both January and February being just slightly above average. However March was the warmest since 2000 and the 6th warmest since records began and April was the warmest since 1955 and the 4th warmest in the region. Only 11 of the 61 days of those months were colder than average.

After a cold streak to start the month of May, it wasn’t until late October that there was another extended period of cold temperatures. But what was interesting was that that apart from a warm week early in July and one late in August the rest of the summer was consistently just a few degrees above average. November again was above average and it wasn’t until December that we had the only below average month of the year.

There were 11 days over 30 degrees during the year, higher than the average of 7 and much higher than the single day over 30 in 2009 and the 2 days in 2008. Even with the vast difference in the last 3 summers, the “end of summer” polls in all those years have resulted in a similar number of people that considered the summer to be great or good: 74% in 2010, 66% in 2009, and 77% in 2008.

For precipitation, the year started off very dry with January being the driest since 1981 and fourth driest in the region since records began in 1914. The months that followed were also dry and by the end of May we only had about two thirds of the average precipitation. This was quickly offset by a very wet June (wettest in over 40 years) and July (wettest in over 15 years) that put us back into the average range.

August saw only a few days of rain, but before an extended drought could start September came in as the wettest single month since 1996 with three days having 30 or more mm of precipitation. Both October and November were average for precipitation while December only had about half of the average.

The final total was 879.3 mm which is close enough the average of 904.0 mm to say that for the second year in the row we had an average year of precipitation.

The most precipitation we saw on a single day was the 62.5 mm on July 23rd which was more than what fell during the entire months of January, February, March, August, or December. The 35 mm that we received that day between 7:45 am and 8:15 am was a 1 in 10 year precipitation event that caused some short term flooding in the area.

The 77.5 cm of snow we saw during the calendar year of 2010 was about half of the average of 159.5 cm. We didn’t get any measureable snow during March at the UW weather station and you have to back to 1946 to find another March like that.

Notable weather days of 2009:

January 27: The high temperature was only -4.1 °C breaking a streak of 14 days of above average temperatures.

March 26: The UW Weather Station blog predicts that the high temperature that day will be the lowest for at least the next 6 months. As it turns out it took until November 28th to see a colder day so it was actually over 8 months before a lower high was seen.

April 1: Thaigo Barolomei wins the UW Weather Station Contest with his guess of 1:00 pm.

May 3: Not really a weather event, but on this day at 5:15 am the UW Weather Station equipment experienced a major failure in the main logger unit. It would take until May 26th before the station was back in operation, resulting in by far the longest period of downtime for the station since operation began in February of 1998. We thank everybody for their patience during that difficult time.

July 5: The high temperature of 33.1 °C was the warmest temperature of the year and the highest since August 1, 2007. While the low temperature that evening was only 21.9°C, the warmest night since August 1, 2006.

July 15: As a big storm came through the area, the temperature dropped 4.3 degrees between 8:15 and 8:30 pm, the largest 15 minute temperature drop of the year.

July 23: A 1 in 10 year event between 7:45 am and 8:15 am saw 35.4 mm of precipitation fall and the day’s total of 62.5 mm was the single wettest day since July 11, 2008.

August 23: The high temperature was 2.4 degrees below average, breaking a streak of 2 weeks of above average temperatures.

September 2: More rain fell during a 24 hour period between the 2nd and the 3rd (51.9 mm) then during the entire month of August (36.2 mm).

October 13: The temperature dipped below zero for the first time since May 11, resulting in 155 frost free days for 2010. This was very close to the average number frost free days in the region which is 154.

Click on the image below to see the temperature chart:

Click on the image below to see the precipitation chart:

December 2010 Summary

2011-01-02T13:40:00.001-05:00

Coldest December in 10 years and the driest one in over 15

Although we didn’t see any extremely cold temperatures in December, it was colder than average for 25 days of the month, including a 20 day streak, while the only significantly warmer than average days came right at the end.

Overall it was 1.5 degrees lower than average, making it the only colder than average month the year and the coldest December since 2000.

With only 36.4 mm of precipitation it was a very dry month with just over half the average of 71.1 mm. This ties 1993 when we also had 36.4 mm and you have to go back to 1969 to a find a December with less.

Most of the precipitation came on the 12th with 15.3 mm in the form of wet snow and as far as total snowfall, we had 28 cm of the average 38.5 cm.

Summary for December 2010:
Maximum Temperature 8.5 °C
Minimum Temperature -17.4 °C
Average Daily High Temperature -2.6 °C (Long term average -0.4 °C)
Average Daily Low Temperature -8.3°C (Long term average -7.5 °C)
Total Precipitation 36.4 mm (Long term average 71.1 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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The reasoning behind 2010 being the 5th warmest year

2010-12-31T17:41:00.004-05:00

In the annual UW Weather Station I had a hard time figuring out where the temperature ranked in the history of the region. The reason is that the records at the Waterloo-Wellington airport only go back to 1971 so to go back further we need to use a station in Kitchener that collected data from 1914 to 1977. Unfortunately between the stations there are going to be differences in equipment, personnel, and of course the location itself making comparison difficult.

When I did a straight ranking of annual temperatures from both stations the results looked like this:

1998 - 9.98
1949 - 8.64
1953 - 8.63
1931 - 8.63
1921 - 8.63
2006 - 8.44
1952 - 8.20
2001 - 8.14
1941 - 8.12
1955 - 8.07
1919 - 8.02
1975 - 7.96
1999 - 7.95
1991 - 7.88
2002 - 7.76

where the bolded number are from the Kitchener station. This would put the 2010 average
temperature of 7.90°C at 13th.

However as there are 7 years of overlap between the stations I was able to calculate that the Kitchener station was an average of 0.74 degree warmer than the Waterloo-Wellington airport station. This difference was very consistent for all 7 years.

So taking the Kitchener station numbers down by that amount make the ranking now look like this:

1998 - 9.98
2006 - 8.44
2001 - 8.14
1999 - 7.95
1949 - 7.90
1953 - 7.89
1931 - 7.89
1921 - 7.89
1991 - 7.88
2002 - 7.76
1952 - 7.46
1941 - 7.38
1955 - 7.33
1919 - 7.28
1975 - 7.22

So this puts 2010 as a tie for fifth overall.

To do a further check I looked for stations within 75 km of Waterloo that had long continuous records. Here are the four that I found:

Toronto airport (1938 - 2009) Missing 1939

1998 - 10.13
2006 - 9.70
2001 - 9.64
1999 - 9.46
2002 - 9.42
2005 - 9.02
2007 - 8.91
1991 - 8.88
1953 - 8.85
1949 - 8.73

London (1941-2001)

1998 - 9.88
2001 - 8.83
1953 - 8.83
1999 - 8.73
1987 - 8.73
1991 - 8.73
1949 - 8.68
1955 - 8.57
1990 - 8.47

Woodstock (1875-2006) Lots of missing years including 1953

1998 - 9.81
2001 - 8.97
1991 - 8.91
1990 - 8.69
1921 - 8.66
2006 - 8.65
1931 - 8.63
1999 - 8.55
2002 - 8.53

Fergus Shand Dam (1939-2006) Missing 1971

1998 - 8.74
2006 - 7.90
1999 - 7.79
2001 - 7.73
1991 - 7.55
2002 - 7.46
1990 - 7.43
1987 - 7.36
1949 - 7.25
2005 - 7.20
1953 - 7.10

Lots of numbers there, but what I was interested in seeing were not the absolute numbers, but the order of the years. It is pretty obvious that 1998 was by far the warmest in the region and the fact that at most of the stations, the same years that were in the top 5 in the Waterloo Region (1998, 2006, 2001, 1999, and 1991) were generally not only in the top at other stations but also higher than 1953 and 1949. All this increased my confidence that the order of the adjusted Waterloo Region data is reasonable.

This is the reasoning behind saying the 2010 was the 5th warmest year in the region since records began back in 1914.

Fall 2010 Summary

2010-12-22T18:20:00.001-05:00

A fall that saw both average temperature and precipitation

Up until the beginning of December it was looking to be a very warm fall. But since the start of the last month there have been only a few days that were above average. This brought the overall temperature for the fall down to half a degree above average, which is within the average range.

The precipitation was relatively well spread out over the season with the only prolonged dry spell occurring between late October and mid-November. The total precipitation was 228.7 mm which is a little higher than the average of 220.9 mm, but still within the average range.

For the second year in a row the total snowfall for the season of 30 cm was below the average of 40 cm and quite a bit lower than 2008 when we had 96 cm.

Summary for Fall 2010:
Maximum Temperature 27.6 °C
Minimum Temperature -17.4 °C
Average Daily High Temperature 8.8 °C (Long term average 8.3 °C)
Average Daily Low Temperature -0.1 °C (Long term average -0.5 °C)
Total Precipitation 228.7 mm (Long term average 220.9 mm)

(Long term averages based on 1970-2000 data for the Waterloo Wellington Airport)

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Warming up

2010-12-15T12:52:00.001-05:00

After a few of the coldest days we have seen in a while (ie. since last winter), the temperature on Wednesday went above -6°C for the first time since Sunday evening.

Storm total

2010-12-13T10:12:00.000-05:00

All together we recorded about 14 cm of snow from the storm on Sunday.

November 2010 Summary

2010-12-05T00:18:00.002-05:00

Again with the hot temperatures and average precipitation

November kept the streak going for 2010 with an overall temperature that was a degree hotter than average. We have now seen above average temperatures for each of the 11 months of the year.

There was a regular hot streak from the 8th to the 14th and then a crazy 25 hours around the 22nd when it never went below 10 °C. On the graphs you can really see the difference in the daily cycle of temperature between the sunny/dry first half of the month and the cloudy/wet second half.

So after that incredibly dry first half of November, the second half made up for it getting us into the average range for the month. The total precipitation for the month was 72.7 mm with almost half of that coming on two wet days (16.8 on the 16th and 17.4 on the 30th).

We are now at 842.9 mm of precipitation for the year, a little above the average for this time which is 830.3 mm. It also looks likely that for the second year in row we will have an overall average year for precipitation.

Summary for November 2010:
Maximum Temperature 16.3 °C
Minimum Temperature -8.9 °C
Average Daily High Temperature 8.3 °C (Long term average 5.9 °C)
Average Daily Low Temperature -1.9 °C (Long term average -1.6 °C)
Total Precipitation 72.7 mm (Long term average 82.3 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Cooling down today

2010-11-23T09:18:00.002-05:00

As sometimes happens, the high temperature for Today occurred just after midnight and it is going to cool down rapidly during the day.

A great way to see just how fast the temperature is dropping is to look at the weather graphs: http://weather.uwaterloo.ca/UWweather_graphs.html

You can also see just how much higher the recent temperatures have been than the average high and low temperatures for this time of year, shown as green horizontal lines on the graph.

Opinions on the clock change

2010-11-11T12:18:00.003-05:00

Now that we have had time to adjust to standard time I have heard and read a lot of opinions on whether or not people like it when the clocks change.

There are of course only so many hours of daylight and that number is going down these days. When we go to Daylight Saving Time in the spring we shift an hour of daylight into the evening.
Thus at this time of year, the clock change takes an hour from the evening and puts it back to the morning (we are now on standard time).

To find out what people think, I have put a poll on the UW weather station blog asking whether people would rather have that extra hour in the evening or the morning or are just indifferent.

As well as voting you can leave a reply to this post giving your reasons.

October 2010 Summary

2010-11-04T11:27:00.002-04:00

Another hot month with above average precipitation

There was a warm stretch at the beginning of the month and one at the end, but no prolonged cold streaks. Thus the overall temperature for October was 1.4 degrees higher than average.

This continues the streak of above average temperatures for each month of the year. However, I compared this year to 1998 (which was the hottest year in the region) and even if the last two months were both 6 degrees above average it still wouldn’t be enough to be warmer than it was in 1998. Note that in the last 10 years, only one time has a month been 6 degrees above average, so I don’t see it happening twice in a row.

We also saw the first frost of the season on the 13th at 3:30 am, this was the first below zero reading since May 11th. The 155 frost-free days this year was about the average for the past decade.

The precipitation was on the high end of average for most of the month, but a few storms in the last week put us just above the average range.

A couple of wet months in a row means that we are now at 770.1 mm of precipitation for the year, a little above the average for this time of year which is 748.3 mm.

Summary for October 2010:
Maximum Temperature 22.5 °C
Minimum Temperature -2.3 °C
Average Daily High Temperature 14.4 °C (Long term average 13.2 °C)
Average Daily Low Temperature 4.4 °C (Long term average 2.9 °C)
Total Precipitation 78.3 mm (Long term average 67.1 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Looking for snow measurement volunteers

2010-10-25T12:59:00.002-04:00

Although we already have a couple, I'm always looking for a few more people who live in north Waterloo to help us out and measure the daily snowfall.

Unfortunately daily snowfall is not something that can be reliably measured with automatic equipment and as snowfall depths are so variable it is good to have a network of measurement locations.

We would provide the minimal equipment that is required but as the title of this post says it is a volunteer position.

Requirements:

- Live in the general area of the weather station, let's say Albert/Weber Street to the east, Erb St to the south, Erbsville to the West and Benjamin Road to the north.

- Have a backyard that is generally open to the sky, but is sheltered from wind and a flat area that is at least aound 4 m by 4 m.

- Able to measure the daily snowfall around 7:30 am on most days between now and early April (or whenever the snow season ends). You don't have to commit to doing it every single day (eg. you can take a vacation for a week or miss the odd weekend), but missing more than a week would be problematic.

Please email: weather@civmail.uwaterloo.ca if you are interested.

First frost of the season

2010-10-13T09:28:00.002-04:00

The temperature dipped to -0.2°C in 3:30 on the morning of October 13th. This was the first time we have seen a below zero temperature since way back on May 11.

Although the date of October 13th is later than the long term average first frost date of October 1st, it is about average for the 12 years of the UW weather station. As well, the 155 frost free days was pretty much the average length of frost free days we have seen in the last decade.

September 2010 Summary

2010-10-10T22:53:00.002-04:00

The wettest month since 1996 that was still very hot

Overall the temperature was a degree above average, but this might not tell the whole story as the daily highs were exactly average while the daily lows were a full 2 degrees warmer than average.

However, it still may have seemed like a cool month as in the past decade September has been the month that has been most consistently above average. We have only had one September in the past 10 years that was colder than the 1971-2000 average (and that was only by 0.1 of a degree). So even though it was full degree above average this year, it was still the third coldest September of the past decade.

It turned out to be quite a wet month, in fact at 154.0 mm it was the wettest month we have seen in the area since September of 1996 (to be clear it was the wettest of any month of the year not just September).

What really got the month up there were 3 days with more than 30 mm of rain: 32.3 mm on the 3rd, 29.9 mm on the 16th, and 37.2 mm on the 38th. Ok the rain on the 16th wasn’t exactly 30 mm, but pretty close.

For the first time this year we have had more than the average amount of precipitation, 691.8 mm compared to 680.7 mm.

Summary for September 2010:
Maximum Temperature 30.6 °C
Minimum Temperature 4.0 °C
Average Daily High Temperature 20.0 °C (Long term average 20.0 °C)
Average Daily Low Temperature 10.3 °C (Long term average 8.3 °C)
Total Precipitation 154.0 mm (Long term average 87.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Still waiting on the first frost

2010-10-04T09:40:00.000-04:00

The lowest temperature we saw was 2.7°C this past weekend.

Thus the wait for the first frost of the season continues.

Possible frost this weekend

2010-09-29T10:44:00.000-04:00

The forecasts have been bouncing around in the last few days, but now both Environment Canada and The Weather Network have us going below zero on Sunday morning and getting pretty close on Saturday morning.

As the average first frost date is October 1st in the area, this year could be pretty much on schedule.

Final results for the Summer of 2010 poll

2010-09-29T10:39:00.001-04:00

(just wanted to put these into a post before I took down the survey)

Final results of the Summer of 2010 poll:

Great (I loved every day of the hot weather): 77 (43%)

Good (A few more cool days in July and August would have been nice): 56 (31%)

OK (A little too much heat, but I'll take it over the cold): 15 (8%)

Bad (My air conditioner got a workout): 12 (6%)

Terrible (Way too hot, I never wanted to go outside): 19 (10%)

Total votes: 179

Summer 2010 Summary

2010-09-22T23:57:00.000-04:00

A hot summer with total precipitation on the high end of the average range

It was a very hot summer, almost 2 degrees above average, making it the hottest summer since 2005. But of course without these last 3 relatively cool weeks at the end, it would have been even warmer overall. There was a big difference between the daytime highs and nighttime lows, the daily maximum temperatures were only a degree above average while the daily minimum temperatures were a full 2.5 degrees above.

As far as precipitation, we had 314.6 mm compared to an average of 274.0 mm, this is still within the average range, albeit on the high end. The rain was not evenly distributed as 4 days accounted for over half of the season's precipitation.

In the UW weather station Summer 2010 poll, it seemed that a lot of people liked the weather we had during the summer. The results were that 42% called it great, 31% good, 8% OK, 6% bad, and 10% called it a total washout. Thanks to the 179 people who entered the poll.

Interestingly, although last summer was very different weather-wise, the poll results this year were pretty much exactly the same as last year. Does this mean that certain people will always love or hate the summer no matter what the weather? And that there are the same number of people that like the hotter summers as like the cooler summers?

Summary for Summer 2010:
Maximum Temperature 33.1 °C
Minimum Temperature 4.0 °C
Average Daily High Temperature 25.3 °C (Long term average 24.2 °C)
Average Daily Low Temperature 14.6 °C (Long term average 12.2 °C)
Total Precipitation 311.4 mm (Long term average 274.0 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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What did you think of the summer of 2010?

2010-09-14T22:40:00.002-04:00

As summer is coming to end next week it is time for the end of summer poll.

If it is before September 22nd you can vote at the top of the UW weather station blog in the five standard categories:

Great (I loved every day of the hot weather)

Good (A few more cool days in July and August would have been nice)

OK (A little too much heat, but I'll take it over the cold)

Bad (My air conditioner got a workout)

Terrible (Way too hot, I never wanted to go outside)

Mystery tower question

2010-09-13T15:01:00.001-04:00

I had a question about a red and white tower about 30 m tall near RIM park in north-east Waterloo.

Apparently (I have not seen it) there is an anemometer on it and the person would like to know if the data are available.

Please leave a comment on the blog if you have any information.

A wet start to the month

2010-09-06T22:27:00.002-04:00

As pointed out by an anonymous commenter on the blog, we had more rain during a 24 hour period between the 2nd and the 3rd of September (51.9 mm) than we did for the entire month of August (36.2 mm).

August 2010 Summary

2010-09-01T21:32:00.002-04:00

The hottest August in 50 years with less than half of the average precipitation

With an overall temperature over 2.5 degrees above average it was the hottest August since 1959. There was little relief from the heat as well, given that there were no days that were significantly (ie. more than 5 degrees) below average.

We still have not seen a month this year that has been below average, making this the warmest first 8 months of the year since 1998, which was the hottest year on record in the area.

It was a dry month with only 36.2 mm of precipitation when the average for August is 87.0 mm. Apart from a couple of days with around 10 mm, the rest of the month's precipitation were just a few sprinkles here and there.

Of course a dry month is going to also put us further behind for the year. So far we have had 534.2 mm in 2010, compared to the average of 596.0 mm at the end of August.

Summary for August 2010:
Maximum Temperature 33.1 °C
Minimum Temperature 7.5 °C
Average Daily High Temperature 26.8 °C (Long term average 24.7 °C)
Average Daily Low Temperature 15.9 °C (Long term average 12.6 °C)
Total Precipitation 36.2 mm (Long term average 87.0 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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A cool day and night

2010-08-27T15:48:00.002-04:00

The high temperature only got up to 20.3°C on Thursday and the low on Friday morning went down to 7.5°C.

These were the coldest daytime high and nighttime low temperatures that we have seen in almost 2 months.

But of course a change is coming with 3 days of predicted highs over 30.

Get me a parka!

2010-08-24T21:41:00.004-04:00

The high temperature was only 21.5°C on Monday making it the lowest daytime high temperature since July 1st.

Still a dry month

2010-08-23T09:51:00.002-04:00

Even with the rain we had over the weekend (about 13 mm) we still have only seen about one third of the average amount of precipitation for the month with a little over a week left.

With the relatively wet June and July it doesn't look like most of the lawns around the area are really showing the effects of the dry August so far.

What does this thing do?

2010-08-16T13:53:00.003-04:00

As this is Waterloo, odds are a lot of people can identify the image below. But for those that don't know, it is called a QR code. Basically it is a method of linking to a website without having to type out the URL. They are typically scanned in using smart phones which is why the QR code below links to the mobile version of the UW weather station site.

By the way, this was sent in by David Carr and I think it is a cool use of new technology.

So is this a useful addition to the UW weather station page? Is it big enough on the homepage? Is it too distracting?

Please leave any comments you have about it.

Northern light show on Wednesday and Thursday morning

2010-08-03T21:40:00.003-04:00

Had a few emails about this, so here are the current estimates for the Northern Light show peaks: 2 am Wed, 1 pm Wed, 8 pm Wed, 2 am Thurs EDT. Remember it may or not be visible in our area and will be most visible outside of the city lights.

(do send along any pictures if you happen to see any)

Here is a good up to date place to find out what is happening:

http://spaceweather.com/

July 2010 Summary

2010-08-01T17:34:00.002-04:00

A very hot July that was also very wet

It was very hot for the first week of the month and then it was just a bit hot for the rest. Overall it was a full 2 degrees above average and about 4 degrees hotter than what we saw last year in July.

The high temperature of 33.1 °C on the 5th was the warmest day since August 1st of 2007 and the 5 days in a row of temperatures over 30 (from the fourth to the eighth) was the first time that happened since 2005. On the night of the 5th (morning of 6th) the temperature only got down to 21.9 °C making it the warmest night since August 1st of 2006.

It was looking like a very average month for precipitation up until the morning of the 23rd, when we received over 35 mm between 7:45 am and 8:15 am. This was a 1 in 10 year precipitation event that caused some flooding in the area. At 65.2 mm it was also the wettest single day since July 11, 2008. (see some pictures of Silver Lake after the storm here: http://uwweatherstation.blogspot.com/2010/07/friday-mornings-significant-rain-event.html )

The total precipitation of 129.2 mm was definitely way above the average of 92.9 mm for the month, but not close to the record of 223.2 mm in 1988.

These last two very wet months have made up for the dry beginning to the year and we have now had the average precipitation for the first half of 2010.

Summary for July 2010:
Maximum Temperature 33.1 °C
Minimum Temperature 7.2 °C
Average Daily High Temperature 27.4 °C (Long term average 26.0 °C)
Average Daily Low Temperature 16.3 °C (Long term average 13.8 °C)
Total Precipitation 129.2 mm (Long term average 92.9 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Friday morning's significant rain event

2010-07-23T11:53:00.005-04:00

We woke up to a significant rain event Friday morning with 35.4 mm coming down between 7:45 am and 8:15 am. This translates to a 1 in 10 year precipitation event.

Although that was definitely the peak of the event, between 7 and 9 am we got around 50 mm.

One factor that probably intensified the runoff was that we had received about 10 mm of rain overnight making the ground just that much more saturated. Thus the rain that hit in the morning was more likely to run directly off into the river systems instead of percolating into the ground.

To show how localized the storm was the Grand River rain gauge in Brantford only recorded about 4 mm of precipitation this morning.

Here are some pictures of the Silver Lake at around 11 am this morning:

You can contrast the water level will the even larger storm we had back in July of 2008:

http://uwweatherstation.blogspot.com/2008/07/record-rainfall.html

Consistent warmth

2010-07-20T22:50:00.003-04:00

It looks like this July we might not have a single day that is more than 5 degrees below average.

Last year 10 days in July (ie. a third of the month) were that much colder than average.

Temperature drop

2010-07-16T08:38:00.003-04:00

On Thursday evening, as the big storm started coming through, between 8:15 pm and 8:30 pm the temperature dropped 4.3 degrees and almost 7 degrees between 8 and 9 pm.

It is very possible that these might end up being the largest temperature drops of the year.

A very hot month so far

2010-07-12T10:12:00.000-04:00

The first 11 days of July were a stunning 2.5 degrees above average.

It is hot out there!

2010-07-05T22:47:00.001-04:00

The high temperature on Monday of 33.1°C was the hottest day since Aug 1, 2007.

Also, if we get the forecast 5 days in a row over 30, that will be the first time that has happened since 2005.

June 2010 Summary

2010-06-30T23:32:00.006-04:00

A warm June that was the wettest in over 40 years

Apart from a 5 day cold stretch at the beginning of the month, the rest of June was pretty warm. Overall it was a full degree warmer than average, despite the fact that the highest temperature was only 28.3 °C, the lowest June high since 1993.

But the real story was the precipitation, at 130.3 mm it was the wettest June since 1967 and the wettest of any month since December 2008. The rain was consistent with a large storm (over 10 mm) occurring at least once a week and 17 days with some precipitation compared to 12 days on average.

But even with this really wet month the precipitation for the first half of the year is still a bit below average. We have had 372.3 mm so far in 2010 and the average at this point in the year is 415.0 mm.

Summary for June 2010:

Maximum Temperature 28.3 °C
Minimum Temperature 5.4 °C
Average Daily High Temperature 23.1 °C (Long term average 23.6 °C)
Average Daily Low Temperature 13.6 °C (Long term average 11.3 °C)
Total Precipitation 130.3 mm (Long term average 80.0 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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1 step forward, 2 steps back

2010-06-28T23:40:00.001-04:00

The updates and rewiring weren't 100% successful, sorry but I am going to have to take off the pressure again until we figure out what is happening with it.

Isolated rain on Saturday

2010-06-21T11:38:00.004-04:00

Looking at the precipitation report from the GRCA you can see that Cambridge was the only location in the area that got any rain this past Saturday. Crazy to see one location get almost 25 mm and Ayr getting 1 mm was the only other station that reported any.

Spring 2010 Summary

2010-06-21T10:27:00.002-04:00

Warmest Spring since 1998 with average precipitation

It was a full 2 degrees above average this Spring, making it the warmest since 1998. The warmth was pretty consistent with only a week of colder temperatures in May and a few in June that were significantly below average.

Although we got around 25 mm more than the average precipitation for the season, this is still within the average range (albeit on the high side). It was also a feast or famine situation with the precipitation, as for most of it we would go a week or two without anything and then have a few very wet days in a row.

Summary for Spring 2010:
Maximum Temperature 31.3 °C
Minimum Temperature -7.1 °C
Average Daily High Temperature 17.9 °C (Long term average 15.9 °C)
Average Daily Low Temperature 6.2 °C (Long term average 4.4 °C)
Total Precipitation 243.5 mm (Long term average 219.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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A wet June already

2010-06-15T23:26:00.000-04:00

After a dry first five months of year (none had more than average precipitation), June has come back with a vengeance.

As of the halfway point of the month we have already had more precipitation (81.6 mm) than the average for the entire month (80.0 mm).

Higher than the maximum incoming solar radiation

2010-06-07T16:10:00.005-04:00

These days near the summer solstice and when there are big puffy clouds in the sky are typically when we get the highest values of incoming solar radiation all year.

In fact the readings are sometimes higher than the maximum incoming solar radiation which confuses some people. One has to remember that the maximum values are the maximum "direct" incoming solar radiation while the instruments we have at the UW weather station measure both "direct" and "reflected" solar radiation.

So on days like today not only is the sun producing a lot of direct solar radiation but those big puffy (and white) clouds are also reflecting a lot of that solar radiation towards the sensor.

Of course you also see really low readings as well when the direct solar radiation is blocked by one of those clouds.

Semi back to normal

2010-06-07T16:10:00.002-04:00

I have taken the "beta" tag off of the website as we now think that the station is somewhat stable.

You may notice that we are using the precipitation gauge that only gives us the 1 hour readings and there are no pressure readings.

I should been better at only putting readings on the station that came from stable instruments, for example, the lack of updated precipitation although it was on the website.

I apologize for the confusion this created last week when it was raining and nothing was showing.

In the future I will do my best to only display readings from instruments that we have confidence in.

But note that the archive will contain all the readings as that's just the way we roll here at the UW weather station.

May 2010 Summary

2010-06-03T16:53:00.003-04:00

We had problems with the equipment at the UW weather station during the month of May. As a result this summary is based on readings from the Environment Canada weather station at the Waterloo-Wellington Airport.

University of Waterloo Weather Station Summary - May 2010

A warm May with average precipitation

It was the warmest May since 1999 with an overall temperature about one and half degrees above average. A cold snap from May 6th to 13th was offset by a very warm end to month where we saw temperature that were more summer-like.

This makes 7 months in a row that the temperature was above average.

The 67 mm of precipitation was a little less than the 75.7 mm average, but this is still within the average range. About 25 mm came down on the very wet May 7th.

Summary for May 2010:
Maximum Temperature 31,8 °C
Minimum Temperature -1.2 °C
Average Daily High Temperature 20.5 °C (Long term average 18.9 °C)
Average Daily Low Temperature 7.8 °C (Long term average 6.6 °C)
Total Precipitation 67.3 mm (Long term average 75.7 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

Getting closer to being back

2010-05-26T21:59:00.002-04:00

Some progress today!

We got the new equipment installed, not all the instruments are working but
hopefully in the next day or two updated readings will start to appear.

But there is also the possibility that some strange readings might pop up so be prepared.

Thank you for your patience.

Station still down

2010-05-17T17:06:00.000-04:00

The necessary repairs are taking longer than we had hoped.

It turns out the device that ran everything at the station is the part that died.

As that part was over 15 years old we have been forced to upgrade to the current model.

Unfortunately this involves a whole new set of programming, so basically it is like starting the station from scratch again.

We will hopefully be installing the new device this week (May 17-22).

We are very sorry for the delay in getting back to updated readings.

Typical last frost day

2010-05-10T10:56:00.002-04:00

Assuming that the last frost day was either on Monday (10th) or will be on Tuesday (11th), it will be a little later than the average last frost day which is May 6th in the area.

However, there is a very large range for the last time the temperature goes below zero as we have seen dates anywhere between the 25th of April and the 21st of May.

April 2010 Summary

2010-05-02T20:58:00.003-04:00

Warmest April in 55 years and finally an average month for precipitation

Just like March, it was another warm month, this one was 3.4 degrees above average, making it the warmest April since 1955 and tied for the forth warmest in the 90+ years of record keeping in the area. As well, the last time we had two consecutive months that were more than 3 degrees above average were the months of January and February of 2002.

We had 24 warmer than average days, 11 that were more than 5 degrees above average and only 3 days that were more than 5 degrees below average. I was also never able to find an April in the area when the lowest temperature was only -2.3 °C or put another way in every other April it always got colder than -2.3 °C.

For the first time this year we had an average month for precipitation with 67.6 mm coming down compared to an average of 76.9 mm. Of course 51.6 mm of this came during a 3 day period early in the month, so the rest of the month was dry.

It has been a dry start to the year with only about two thirds of the typical amount falling during the first four months of the year. In the past 45 years this is the second least amount of precipitation we have had at this point in the year (we had a little less in 2003).

I could have done this last month, but I think it is now safe to call an end to the 09/10 snowfall season. We only had 78 cm during the month which is less than half of the average amount (159.5 cm) and a lot less than what we saw during the two previous winters – 257.7 cm in 07/08 and 235 cm in 08/09.

Summary for April 2010:
Maximum Temperature 26.3 °C
Minimum Temperature -2.3 °C
Average Daily High Temperature 15.7 °C (Long term average 11.4 °C)
Average Daily Low Temperature 3.0 °C (Long term average 0.6 °C)
Total Precipitation 67.6 mm (Long term average 76.9 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Power outage this weekend

2010-04-19T15:59:00.000-04:00

The building containing the computer that runs the weather station website will be part of a utilities shutdown this upcoming weekend.

This may cause the weather station website to be unavailable at times, website updates will continue as soon as possible after any interruption.

Cold day on Friday

2010-04-11T13:50:00.003-04:00

When the temperature only got up to 2.1°C on Friday, April 9th it was 6 degrees below average for that day. The last time we had a day that was that much below average was way back on January 29th when it was 8.5 degrees below.

2010 UW weather station contest winner

2010-04-01T13:45:00.002-04:00

Although on a day like this we are really all winners, there can only be one winner of the 2010 UW weather station contest.

This year's winner is: Thiago Bartolomei

who correctly chose a time of 1:00 pm on April 1st as the first time the temperature at the UW weather station would go above 20C and for the second year in a row we have a birthday winner!.

In second place we have:

John Jongerius.

Thanks to everybody who entered the contest, we hope you had fun with the
contest, and will enter again next year.

Once again we would like to thank The Waterloo Store who sponsored this year's prizes.

As well as taking home some cool prizes, the winners will also become
members of the Waterloo Weather Station Contest Hall of Fame.

March 2010 Summary

2010-04-01T13:43:00.001-04:00

Warmest March in 10 years with below average precipitation and no snow

It was a very warm March with only 3 colder than average days, which all came at the end of the month. Overall it was 3.4 degrees above average, making it the warmest March since 2000 and the 6th warmest since records began in the region.

There wasn't that much precipitation overall with only 48.4 mm falling compared to an average of 70.6 mm. This continues the dry trend as we are only at 107.2 mm where we would expect 187.6 mm at this time of the year. A majority of the precipitation fell during a 3 day period between the 12th and the 14th.

But the big story is the lack of snowfall during the month, unfortunately it gets a bit difficult to directly compare to previous measurements, as the determination of snowfall amounts is a bit subjective. Although we didn't record any snow at the UW weather this March, the Environment Canada Waterloo-Wellington II station did have one day with 1.0 cm and another day with trace snowfall. You have to go back to 1946 when there were only 2 Trace amounts recorded to find a March that had less snow.

So I think we can safely say it was the lowest snowfall for March in over 60 years and at least very close to the lowest snowfall total as far as records go back in the area.

Summary for March 2010:
Maximum Temperature 17.3 °C
Minimum Temperature -13.0 °C
Average Daily High Temperature 7.9 °C (Long term average 3.5 °C)
Average Daily Low Temperature -3.3 °C (Long term average -5.6 °C)
Total Precipitation 48.4 mm (Long term average 70.6 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Believe it when I see it

2010-03-29T22:18:00.002-04:00

As of Monday evening, The Weather Network is forecasting a high of 28°C for Friday with a Humidex of 34. If that were to come to pass it would be the highest temperature seen in April since 1990. Keep in mind that is for the entire month of April, I'll have to dig deeper into the data to see how it ranks for the first half of April.

But Friday is still a while away, so we will see if that forecast holds up for the next couple of days.

Wednesday or Thursday?

2010-03-29T11:20:00.003-04:00

It looks like the weather station contest will definitely come to an end this week. Right now Environment Canada is calling for a high of 19 on Wednesday and 23 on Thursday, looks like it has to happen on one of those days.

Cold this be the coldest day for the next 6 months?

2010-03-26T10:43:00.001-04:00

Whatever the high turns out to be on Friday, it looks like it might be the coldest daytime high for a while. The short and medium range forecasts all point to major warming this week and then staying near average after that.

Assuming we make it through the start of April without a colder day, it is likely we won't see another one this cold till September or even October.

Winter 2009/2010 Summary

2010-03-20T13:39:00.001-04:00

A warm winter with very little snow

Although the first months of the winter were only slightly warmer than average, the extremely warm temperatures of March made the entire season much hotter than average. Overall the temperature was 1.5 degrees higher than average, this makes it the warmest winter since 2005/2006 and the 3rd warmest of the last 10 years.

Also significant is that there weren't really any extended cold snaps. To put some numbers on it, we never had more than 2 days in a row when the temperature was more than 5 degrees below average. The last time we had a winter like that was back in the winter of 2001-2002.

But the real story of this past season was probably the lack of precipitation, in particular snow. We got 113.2 mm of precipitation (this is a combination of rain, snow, sleet, freezing rain, and whatever else nature threw at us) compared to an average of 184.5 mm, so that's about two thirds of the average.

Unfortunately when it comes to snow, considering only the amounts during the 3 months of winter doesn't really tell the entire story. For now, I'll just say that for the winter season we only had 54 cm of snow which is about half of the average and the lowest since the winter of 1981/82. The full story will come after the end of the snowfall season, which goes until there is no reasonable expectation of any more snow (probably sometime in April).

An unscientific poll done on the UW weather station blog revealed that although most people thought the winter was great (38%), there were still a good number (21%) that wanted a real winter. I had a feeling it would be a polarizing kind of winter that either you really liked or really hated.

Final poll tally: Great 87 (38%), Good 40 (17%), OK 34 (15%), Bad 17 (7%), Washout 48 (21%), total number of votes: 226.

Summary for Winter 2009/2010:
Maximum Temperature 16.9°C
Minimum Temperature -21.5°C
Average Daily High Temperature -0.3°C (Long term average -1.4°C)
Average Daily Low Temperature -8.0°C (Long term average -9.8°C)
Total Precipitation 113.2 mm (Long term average 184.5 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Winter 2009/2010 poll

2010-03-11T21:52:00.003-05:00

Spring officially starts next week so let's find out what everbody thought of the winter. The final numbers aren't in but obviously it was a warm and dry winter.

You can cast your vote on the UW weather station blog and just like the summer poll there are five categories (great, good, OK, bad, and washout).

I'm not really sure how this one is going to turn out.

Warmest day in 3 months

2010-03-08T15:18:00.003-05:00

The high temperature on Monday of 8.8°C was the highest temperature we have seen since December 2nd (9.2°C).

February 2010 Summary

2010-03-01T12:07:00.002-05:00

Another dry month with average temperatures

Apart from a couple of colder nights in the first week of the month, the temperatures in February stayed very much within the average range. The daily high temperatures were never more than 5 degrees away from the average while the lows only occasionally got out of that range, mostly on the warm side. But even these warm nights couldn’t get the temperature out of the average range overall.

Another dry month with only 30.9 mm compared to the average of 51.3 mm. Almost half of that came during the 22nd when 13.2 mm of precipitation came down. That storm prevented it from being a historically dry month, but it was still below average.

The total snowfall of around 30 cm was pretty much exactly the long term average, but as most of it came during one storm and as we had not seen much so far this winter it sure did feel like a lot. However what we were missing in February was the rain component of precipitation which is usually around 25 mm.

With a dry first two months of the year, the total precipitation for 2010 of 58.8 mm is only about half of the 117.0 we would expect by this time of year.

Summary for February 2010:
Maximum Temperature 3.1°C
Minimum Temperature -19.1°C
Average Daily High Temperature -2.0°C (Long term average -1.9°C)
Average Daily Low Temperature -8.7°C (Long term average -10.5°C)
Total Precipitation 30.9 mm (Long term average 51.3 mm)

(Long term averages based on 1971-2000 data for the Waterloo Wellington Airport)

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Better late than never

2010-02-25T13:06:00.002-05:00

The entry period for the 2010 edition of the UW weather station contest has started.

See all the details and enter the contest here.

The entry period ends at 3 pm on Thursday March 4th, so get those guesses in.