July 2020 Review / August 2020 Preview

When you think back to the covid-summer of 2020, do you think you will remember the first 3 cool & rainy weeks of July, or the final hot one?

High Temperatures

The first few weeks of July 2020 weren't exactly cold, but there was a total lack of hot days.

The grey band in the middle of this chart is the 25th-75th percentiles for our High temperatures, which is where the temperatures will fall about half of the time. In the first part of the month July 1, 2, 7, 8, 12 & 13 were all below the 25th percentile and were pretty chilly for July. And only 1 day was actually above the 75th percentile into "hot" territory: July 16th at 27.1°C.

That all changed on July 27th when the temperatures finally (finally) jumped above average. They stayed there until the end of the month, and the forecasts say they will continue at least a little longer into August.

At the end of the month we finished with 17 days below average (including a 30-year coldest High), and 14 days above average.

In terms of the individual temperatures we didn't hit 30°C, but we did end up with 10 days at 25°C. That's below the July average of 12 days, but above years like 2019, 2011, 2010...

July 2020's average High of 23.4°C was on the cooler side of recent years, ranking as 12th warmest since 2000.

Hot Days So Far...

So far this summer we have had 14 days hit 25°C, which ties what we had last year in 2019. It's about 20-30 fewer than the very hot summers of 2015-2018, though. And it's a bit below the long-term average, which is about 20 Highs at 25°C by this point in the summer.

For slightly hotter days, we had our first 28°C High quite late on July 27th. We have now had 3 of those, while the average is around 6. And for milder 20°C days we have had 57, and that is below 2015-2018, but is pretty close to the long-term average.

Low Temperatures

The Low temperatures look a lot like the Highs, although at the end of the month we were right at the top of our 30-year range (and 0.1~0.2°C from the records).

The range of our July Low temperatures is usually very tight, and this year we had 4 nights below 10°C, 4 nights above 15°C, and everything else was between 10-15°C.

Warm & Cold Months

July 2020's average High of 23.4°C was just a bit below the recent average of 23.7°C and ranked as #67 our of 140. That average has stayed fairly level since records began in the 1880s, starting at 22.6°C, and rising as high as 24°C in the 1930s, and then dropping down to 22.4°C in the late 1990s.

July 2020's average Low of 12.9°C is right on the recent average, and ranks as #13 out of 140. While the July Highs have stayed fairly constant over the years, the average Lows have steadily increased from 8.5°C a century ago to about 13°C today.

Usually in these monthly reviews we talk about the mean temperatures (High & Low) of each month, but this is the middle of summer, and what people really care about are the Highs. So sticking with the Highs temperatures, in this chart the bubbles represent the average Highs for each month going back to 2000. These are compared to the 20th century average, and so big, orange bubbles were warmer than the 20th century average, and big, blue bubbles were colder.

You might notice that it has been a while since we have seen an orange bubble, because the last "warm" (above-average) Highs that we saw were back in February. Highs in March & April were both about 2°C below the 20th century average, and May, June & July 2020 barely show up here because they were so close to average.

So far during what we might call "summer" 2020 hasn't had any hot months, and it joins 2019, 2010, 2009, 2008, 2005, 2004 & 2000 which all had average-to-cool Highs for May through July. In 2019 that continued through August & September, and we didn't get another "warm" month until November. But hopefully August will turn things around for 2020.

Across the Country

Here we are taking a look at the Highs for July 2020 across the country, and there was quite a wide range. St. John's, Calgary & Vancouver were all 1°C or more below their 20th century averages, while Toronto, Ottawa & Montréal were 3.5~4°C above theirs.

 

This is a quick look at Toronto's Highs for July 2020. Their average High for the whole month was 30.3°C, which was the 2nd highest since 1880 (1921's average High was 31.2°C). Ottawa and Montréal are available in the dropdown on the upper right, and they look similar.

Monthly Precipitation

Heading back to Edmonton, and switching over to precipitation, in July Blatchford received 121.2mm which was its 27th rainiest July since 1880 (and below the 163.4mm in 2019). The International received 95.3mm, which was also its 27th rainiest, although those records only go back to 1960 (and it was also below the 118.6mm in 2019).

July's average precipitation is 90.8mm, so the International was just a bit above that, while Blatchford was above the 75th percentile and into the realm of "lots of rain." And looking at the chart June and May also both had lots of rain at both stations.

Blatchford's May-June-July total of 319.6mm was actually its 5th highest since 1880 (1901 leads with 410.4mm). The International's 310.1mm was its 3rd highest May-June-July since 1960 (2010 had 332mm).

Days With Rain

July averages 15 days with rain, and in 2020 Blatchford recorded 17 days while the International had 20. So it was not as rainy as it might have seemed. July is usually our rainiest month, and from mid-June through mid-July is our little monsoon season.

Precipitation So Far...

For 2020 so far the International has recorded 383.8mm of total precipitation (rain + snow), and Blatchford is just a bit below that at 374.5mm. The average for this time of year is 300mm, so we are definitely above average, and things really took-off in May, June & July after our very dry April.

August Temperatures

For August the daytime Highs are above 20°C most of the time, with typically about 25 warm days each month. We also average a week or two of days above 25°C, but 30°C days only happen about half of the time in August. For the Low temperatures it should be a lot of the same 10-20°C orange which we saw for July, but with a few more nights in the 5-10°C range, and every 5 years-or-so a night below 5°C. And also, August's average precipitation is about half of July's.

August 2019 was pretty blah, but that followed a string of warm years from 2011-2018. So hopefully last year was the anomaly, and summer 2020 actually hangs around for awhile this time.