Sunday, December 2, 2018

November 2018 Summary

A wet November that was the coldest in over 20 years

The colder temperatures that started in mid-October continued throughout November, with an overall temperature over 2 degrees below average it was the coldest November since 1996.  This put it at the 5th coldest in the over 100 year history of weather records in the region.  As well, the low temperature on the 22nd of -16.8°C was the coldest November temperature since November 23rd, 2000 when it was -17.9°C.

The total precipitation for the month of 93.4 mm was only a bit above the average of 87.1 mm, but enough to put into the above average range.  This puts the total for the year at 878.5 mm compared to the average of 832.9 mm.

The real story of the precipitation was the 21.5 cm of snow we received in the first half of the month, this is the most for the first half of the month since 1995 when we had 25 cm.  The rest of November only saw a little more resulting in a total of 23.5 cm, which is still a lot more than the average of 13 cm for the month.

Summary for November 2018:
Maximum Temperature 13.5°C
Minimum Temperature -16.8°C
Average Daily High Temperature 3.0°C (Long term average 6.3°C)
Average Daily Low Temperature -2.4°C (Long term average -1.4°C)

Total Precipitation 93.4 mm (Long term average 87.1 mm)

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

Thursday, November 1, 2018

October 2018 Summary

A wet October with average temperatures

You can forget what the calendar said, fall really started this year on October 12th, you can see from the temperature graph just what a contrast there was between the first 11 days of the month and next 20.  In fact the average temperature during the first part of the month was 10 degrees higher than the second part.

Putting all those numbers together results in the overall temperature coming out exactly at the 1981-2010 average, although it may have seemed colder than that as it was the coldest October we have seen in the last 10 years.  The first time the temperature went below zero was on the 14th at 1:15 am (this is about the average for the last 20 years) resulting in a frost-free season of 167 days (which is just a bit longer than the average).

It was really wet at the start and end of the month, with over half of the month’s total of 94.2 mm coming during the first two days and the last day of the month.  As this month come in above average, it joins 9 of the last 10 years that were wetter than average.  This wet month also pushes the total precipitation in the first 10 months of 785.1 mm above the average of 750.6 mm.

Summary for October 2018:
Maximum Temperature 28.5°C
Minimum Temperature -2.6°C
Average Daily High Temperature 12.7°C (Long term average 13.5°C)
Average Daily Low Temperature 3.7°C (Long term average 2.9°C)
Total Precipitation 94.2 mm (Long term average 67.4 mm)

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

Tuesday, October 2, 2018

September 2018 Summary

A very hot and somewhat dry September

The month of September saw 2 different heat waves, it started with 5 days of temperatures close to 30°C and then another 5 that were above 25°C around the middle of the month.  Although there were a few cooler days in between, the average temperature was almost 3.5 degrees above average.  This resulted in it being the 5th warmest September in the 100+ years of records in the region.

A couple of other random facts about this past September: The 5 days 30°C or over were the most since 1952.  The average low temperature was 4 degrees above average, this is the third highest in the historical record.  This month continues the pattern of warm Septembers we have seen recently, with only 1 in the past 20 years slightly below the 1981-2010 average and the rest above.

A dry 10 day period in the middle of the month resulted in the total precipitation (62.8 mm) coming in well below the average (87.8 mm).  The amount of precipitation we have seen so far this year of 690.9 mm is just slightly above the average of 683.5 mm.

Summary for September 2018:
Maximum Temperature 31.9°C
Minimum Temperature 3.4°C
Average Daily High Temperature 23.1°C (Long term average 20.4°C)
Average Daily Low Temperature 12.7°C (Long term average 8.6°C)
Total Precipitation 62.8 mm (Long term average 87.8 mm)

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

Sunday, September 2, 2018

August 2018 Summary

A hot August that was also wet

Well that was a very hot August, coming in at 2.8 degrees above the 1981-2010 average making it the second warmest in the past 20 years and in the top 10 in the 100 years of data in the region.  It was a consistent warmth with the average temperature of only one day (the 22nd) being below average.

Although the days were warm, the heat didn’t go away overnight as the daily low temperatures were the warmest in 20 years.  Which means that if you didn’t have air conditioning it may have been difficult to sleep.

Despite a dry period of about a week, there were also 3 days above 20 mm of precipitation resulting in a total for August of 110.7 mm compared to the average of 83.9 mm.  This wet month brought the total precipitation for the year of 628.1 mm back above the average of 596.0 mm for this time of year.

Summary for August 2018:
Maximum Temperature 31.9°C
Minimum Temperature 10.5°C
Average Daily High Temperature 27.1°C (Long term average 24.8°C)
Average Daily Low Temperature 16.3°C (Long term average 12.9°C)
Total Precipitation 110.7 mm (Long term average 83.9 mm)

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

Wednesday, August 1, 2018

July 2018 Summary

A hot and very dry July

We have now had our third month in a row of above average temperatures with July coming in at 1.5 degrees warmer than average.  However, it was the tale of the two halves of the month with the first half being 2 degrees warmer than the second half.  That first half of the month also saw all of the 10 days that were above 30°C, something we only see 3.5 times on average in July.

The bigger story was the lack of rain during the first 15 days of the month, which combined with the high temperatures, made it hard for non-irrigated vegetation.  We broke that drought with 23.4 mm on the 16th followed by what was a pretty average rest of July.  However, this could not fill the deficit and the final total of 51.2 mm was only a little more than half the average total of 98.6 mm.

But even as hot and dry as that seems, note that we only have to go back to 2012 to find a July that was both hotter and drier.

This dry month brought the total precipitation for the year of 517.2 mm back down closer the average of 509.0 mm.

Summary for July 2018:
Maximum Temperature 32.9°C
Minimum Temperature 8.4°C
Average Daily High Temperature 27.9°C (Long term average 26.0°C)
Average Daily Low Temperature 15.1°C (Long term average 14.0°C)
Total Precipitation 51.2 mm (Long term average 98.6 mm)

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