May 2020 Review / June 2020 Preview

It's time for the month-in-review for May, 2020.

High Temperatures

Our high temperatures for May 2020 were split with 16 days above average and 15 days below. We didn't have any exceptionally hot days, but May 10th's 7.5°C was near the bottom of the 30-year range, and May 22nd's 6.9°C was getting pretty very close to the record-coldest-High of 6.0°C.

Looking at the numbers we had 11 Highs hit 20°C, which is basically right on the average. We also had one High hit 25°C, while we average about 3 of those. Recently 2016-2019 all recorded 30°C temperatures in May, but 2020 ended that 4-year streak.

For cold Highs we didn't record any Highs below 5°C, and had only 2 below 10°C, and that's all fairly typical.

Low Temperatures

Our Low temperatures for the month were also split with 16 days above average and 15 days below. May 30th's Low of 12.5°C was the warmest in 30 years, and everything else was fairly typical.

Blatchford didn't record any Lows below freezing in May 2020, with the closest on May 13th at 0.9°C. May averages about 3 frosts each year, but about half of the time May is frost-free at Blatchford.

Final Frost

Blatchford's average final frost is on May 6th, but for the winter of 2019-2020 it was back on April 19th. That is very early, and in recent years only 2012 & 1998 had an earlier date, with both on April 18th.

This chart also has data for several of the outlying stations (accessible in the upper-right corner), and the final frost in Stony Plain was also April 19th, in St. Albert & Namao it was May 13th, and at the International Airport it was all the way at the end of the month on May 28th.  

Warm & Cold Months

For a bit more historic context here we have the average High temperatures for the month of May going back to 1881. And 2020's average High of 17.3°C was our coolest May since 2014 down at 15.4°C, but it but was still very close to the long-term average and ranked as #83 warmest out of 140.

May is one of the months where our average High temperatures have not changed much over the years. That is not the case for the Lows, though:

The average Low temperature for Low has increased by close to 4°C since records began. May 2020's average Low of 5.7°C was warmer than 2019's 5.4°C, but was still a little cool for for recent years. But overall though it ranked as #37 warmest out of 140.

When we combine the Highs & Lows the mean temperature of May 2020 was just a little bit warmer than the 20th century average. Its small bubble here is on the warmer, orange side of things. Some recent Mays which were cold enough to be on the blue side were 2014, 2010, 2009, 2004, 2003, 2002, 2000...

Looking across the country Vancouver's May was 1.2°C above their average, while Toronto's was -1.3°C below theirs.

Toronto's May was interesting, though:

For Toronto (and Ottawa and Montréal) May 2020 started very cold, and ended very warm. The central cities were all at the bottom of their range at the beginning of the months, and were setting records at the end of it.

Snow

Hopefully we won't see this chart again for a few months, but we should talk about the fact that the International did record 2.4cm of snow on May 4th. We get snow about half of the time in May, and this was one of those years. 2020 and 2019 had snow, 2016-2018 didn't, 2014 & 2015 did, 2011-2013 didn't...

That brought our snow total for the winter of 2019-2020 to 128cm, which is basically right on our average.

...and the International went 210 days from the first snowfall of fall on October 7th to the last day (presumably) on May 4th.

Precipitation

For overall precipitation Blatchford recorded 78.8mm and the International recorded 97.5mm. Our average for May is 50.1mm, so this was a pretty precipitation-y May, but in recent(ish) years 2016, 2010 & 1999 all crossed the 105mm mark.

Both station recorded 12 days with precipitation in May, compared to an average of 11 days.

And that brings our total precipitation for the year so far to 134.3mm at Blatchford which is about average, and to 174.7mm at the International.

June Temperatures

For June temperatures usually about half of the month has Highs above 20°C, and there is also maybe a week of days above 25°C. Last year June 2019 was pretty typical, but then we entered into the summer-that-wasn't. Before that 2018, 2016 & 2015 all had warm Junes, with almost 2 weeks of 25°C days. For Low temperatures the last time that Blatchford had a frost in June was way back in 1942.