Thursday, February 2, 2017

January 2017 Summary

A wet, warm, and “dreary” January

There were four cold days in the first part of the month, but that was about it for the really cold weather.  As well as a few days in the high single digits we also saw 12 days in a row above zero, which is something that we haven’t seen in January since 1944.  Put that all that together and it is not surprising that overall it was over 3 degrees above average, making it the warmest January since 2006.

With the 111.2 mm of precipitation in the month it was the second highest total in the last 18 years (2013 had a bit more with 114.7 mm), while most of it (81.4 mm) fell during the very wet first half of the month.  Of that precipitation there was only 20 cm of snow, less than half of the average of 43.7 cm.

Then we get to the “dreary” question.  The background is that at the UW weather station we measure the amount of incoming solar radiation, which is correlated to the number of hours of sunshine but not technically exactly the same thing.  Also keep in mind that this is the only source of this kind of data in the area, so records only go back to the start of the weather station in 1998, unlike precipitation and temperature which have records going back to 1915. 

So based on what we measure, the overall average of 47 Watts per square metre of incoming solar radiation was the lowest January value in the history of the station and much lower than the average of 81.7 W/m2.  Also I made an arbitrary and non-scientific criteria that if a day never had a reading of over 200 W/m2 then it was a “dreary” day.  Using this, the number of dreary days we had was 13 this January putting it well above the average of 7.5 and again the most we have seen in that past 19 years.

Summary for January 2017:
Maximum Temperature 8.2°C
Minimum Temperature -20.9°C
Average Daily High Temperature -0.1°C (Long term average -2.6°C)
Average Daily Low Temperature -6.4°C (Long term average -10.3°C)
Total Precipitation 111.2 mm (Long term average 65.2 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Sunday, January 22, 2017

Longest January streak of above zero days in a while

As of January 22nd we have had 8 days in a row of days with above zero temperatures and the current forecast is for 4 more.  If we get to 12 days it will be longest streak of above zero days since we had 13 back in 1944 from Jan 19 to 31.

Note that this only counts days in January, for instance 2007 started with 8 days above zero, but this was after 23 to end off 2006, so the total streak there was 31 days, just not all in January.

Tuesday, January 10, 2017

2016 Summary

University of Waterloo Weather Station Annual Summary - 2016

Considering that April was the only colder than average month during the year, it is not that surprising that 2016 came in as one of the warmest we have seen in the 100 years of weather records in the region.  Overall the average temperature was 8.69ºC putting it behind only 2012 and 1998.

The year started off in the middle of the very warm winter of 2015-16 resulting in the first 3 months being all warmer than average, this included a high temperature of 14.2ºC on the third of February which was the highest February temperature we have seen in the region.

Things turned around in April with the only colder than average month of the year that was also the fourth coldest April in the region’s weather records.

The warm end of the Spring in May transitioned into the hottest summer we have had since 1955 and the third highest overall.  The 19 days above 30ºC during the summer contributed to the 27 we had in total for year, this is much more than the average of 8, but much less than the 49 we saw in 1955.

This then continued into the fall with September to November all coming in at over 2.5 degrees higher than average including: September being the warmest since 1959 and the fifth hottest overall and November the sixth warmest and the most days over 10ºC at 20.  But as we have seen a lot of warm Fall seasons lately, this Fall wasn’t that significant even these really warm temperatures.

As often happens there were wet and dry months during the year, for 2016 the year started with a few average months for precipitation.  Then March came in over twice as wet than average, but this quickly changed as for the most part it was a very dry summer.  It would have been historically dry if not for a 10 day period in August when almost 150 mm fell, this resulted in August being the 7th wettest all time.

For the rest of the year we saw pretty much average precipitation which helped in putting the final total within the average range.  The final total came in within the average range at 891.0 mm, which is a little below the average of 916.3 mm.

As for snowfall, we saw 100.5 cm of snow since the beginning of January, which is about average for that time of year.  But the 75.5 cm in the second half of the year (mostly from December which saw almost twice the average for the month) put the total for 2016 of 176.0 cm which is above the annual average of 159.7 cm.

So the final story of 2016 is the overall heat during the year and how dry it was during most of the summer.  But there wasn’t a whole lot in terms of extreme events, in fact in the list of extremes that are listed on the next page there was not one that was exceeding during this past year (of course this will get harder as more data is added to the record, but usually we have seen at least one or two extremes every year).

Summary for 2016:

Average Daily High Temperature: 14.10°C (average 12.05ºC)
Average Daily Low Temperature: 3.28°C  (average 1.94ºC)
Total Precipitation: 891.0 mm (average 916.3 mm) 

(averages are calculated from 1981-2010 data for the Waterloo-Wellington Airport)
Click on the image below to see the temperature chart:

Click on the image below to see the precipitation chart:

Tuesday, January 3, 2017

December 2016 Summary

A wet and snowy December with average temperature 

There was a much colder than average week in the middle of December that was offset by a warmer start and finish to the month, resulting in an overall temperature of 0.3 degrees above average.  This put the month within the average range for only the second time this year compared to 1 below average month and 9 above.

The precipitation was nicely within the average range for most of the month, but a few storms in the last week (including the rain on Boxing Day) resulted in the total finishing above average.  The total of 91.0 mm was well above the average of 71.2 mm.

With a total snowfall of 73 cm, it was the snowiest since 2008 (when we had 95.5 cm) and almost double the average of 37.2 cm.

Summary for December 2016:
Maximum Temperature 8.6°C
Minimum Temperature -14.9°C
Average Daily High Temperature -0.3°C (Long term average 0.2°C)
Average Daily Low Temperature -5.6°C (Long term average -6.8°C)

Total Precipitation 91.0 mm (Long term average 71.2 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)

Thursday, December 1, 2016

November 2016 Summary

Another warm November with average precipitation

It turns out that this November was really close to last November in terms of both temperature and precipitation.  For temperature it was just over 3 degrees above average, tying it with last year for 6th warmest since records began in the area 100 years ago.

First fun fact, although the overall temperature was only tied for 6th, there were lots of temperature variations between the daytime and nighttime temperatures at the start of the month.  This resulted in the average of the daily high temperatures of 10.8°C coming in as the highest daily high temperatures for November.

Second fun fact, there were 20 days when the temperature was over 10°C in November, the highest number in the historical records in the region.

From the temperature graph you can see that the grey “Vancouver” weather started on the 20th with little variation between the daytime and nighttime temperatures.

The precipitation total was 70.2 mm (compared to 68.2 mm last year), although this is below the average of 87.1 mm, it is within the average range for November.  The amount of precipitation for the year so far is 799.6 mm which is below the average of 832.9 mm.  It also means that we only need about 50 mm in December to get within the average range for 2016.

And yes we have to start talking about snow, however, there was only 2.5 cm recorded compared to the November average of 13 cm.

Summary for November 2016:
Maximum Temperature 20.9°C
Minimum Temperature -5.9°C
Average Daily High Temperature 10.8°C (Long term average 6.3°C)
Average Daily Low Temperature 0.4°C (Long term average -1.4°C)
Total Precipitation 70.2 mm (Long term average 87.1 mm)

(Long term averages based on 1981-2010 data for the Waterloo Wellington Airport)