July 2021 Review

It's time to take a look back at Edmonton weather for a fairly eventful July, 2021.

(if you are reading this in the distant future some of the dashboards below may have updated to reflect new data or formatting, or they may be broken, or they may no longer make sense. To see the original images for this post refer to this twitter thread.)

High Temperatures   

July 2021 started with the end of a heatwave, and it stayed quite warm through mid-month. Then the smoke rolled in and we set a record coldest-High for July 18th of 13.9°C. And then it warmed up again, and ended with a new record High of 31.3°C for July 31st. 

Overall 8 Highs were below average, and 21 were above.

 

In July 2021 we had 21 Highs reach 25°C, compared to an average of 12 for July. That included 7 at 30°C, compared to an average of 2.4. We also had one July High below 15°C, which hadn't happened since 2014.

Hot Days So Far   

For hot days so far we have had 13 Highs hit 30°C. That is tied for 2nd with 2002 and 1933, and it just behind the record of 14 from 1961. 

We have also had 12 Highs hit 31°C, which is a record. 2002 is in 2nd place with 9 31°C days, and then 1933 and 1936 both had 8.

Our peak 30°C season lasts until about August 18th (after that they become much less frequent), so we might see some more this summer.

 

For 25°C Days we have had 36 so far, and on average we will get another ~10 in August. 2020 and 2019 only had 23 and 20 respectively during the entire summer, while 2014-2018 were all up in the range of 40-55.

Low Temperatures   

For Low temperatures July 2021 started with the heatwave, and set new warmest-record Lows on July 1st at 23.4°C (the warmest overnight Low ever recorded in Edmonton), as well as on July 2nd, 3rd, and then one more on July 15th.

Overall 25 Lows were above average, with 6 below.

 

For the overnight Lows, in July 2021 we didn't have a single one below 10°C. Recently that had only happened in 2016, 2007 and 2006. On average we get about 4 of those cooler nights each July.

Warm and Cold Months   

Overall July 2021's average High of 25.9°C ranks as Blatchford's 6th warmest July, while the average Low of 14.9°C is #2 warmest.

2007 was the warmest July on record, with an average High of 26.6°C and Low of 15.2°C.

July 2021 Across Canada   

Looking across Canada July 2021 was above average in the west, and below average in the east. That ranged from Winnipeg Highs at 3.5°C above their July average, to Ottawa at 1.4°C below theirs.

 

This chart is a little messy, but on the prairies July 2021 average temperatures were mostly top-10ish. For Edmonton it was the Highs and the Lows, for Calgary the Lows, for Regina the Highs and the Lows, and for Winnipeg the Highs.

 

...while in central and eastern Canada July 2021 was nowhere near the top-10.

June + July

...July was Edmonton's #6 warmest July, and June was #1 warmest June. Together, they are our warmest June + July on record, by a pretty convincing margin. 2021's average High of 25.4°C beats 2002 at 24.7°C and 2015 at 24.6°C. The average Low of 14°C beats 13.1°C from 2006 and 2007.

 

...and the hot June + July was common across the prairies, with top-10 average Highs for these 4 cities, and top-10 Lows for Edmonton, Calgary, and Regina (Winnipeg's Lows were 21st warmest).

Precipitation

On average July is our rainiest month, with June as #2. Together June and July average 160mm of precipitation.

In 2021 Blatchford received 45.1mm, which is its #1 lowest since 1881. The airport's 81mm was its #3 lowest since 1961. And Stony Plain's 47.3mm is its #1 lowest since 1966.

 

On average July has 15 days with measurable rain, and in 2021 the International had 9, Stony Plain had 6, and Blatchford was down at 4.

 

For the year so far Blatchford's 130mm of precipitation is its #2 lowest full year on record, after 1889 with 119mm. The airport's 213mm is its 6th lowest, and Stony Plain's 138mm is its lowest. The average for the end of July is 294mm.

 

This is another messy one, but it has the precipitation for all of the local stations. 

The Airport is the outlier with its 213mm. St. Albert and New Sarepta are both around 170mm, and then the rest are below 150mm.

Precipitation Across Canada

This chart is a little messy again, but it has precipitation for cities across Canada.

The only city here with above-average precipitation in 2021 in St. John's, and that is just a bit above average. Winnipeg is having its driest year on record, after a series of dry years.

August Temperatures

Thinking ahead to August, on average we have 25 Highs which reach 20°C, including ~10 above 25°C. And about half of the time August hits 30°C. Most Lows are in the 10-15°C range, but about half of the time August will have a night below 5°C. And August is our 3rd rainiest month averaging 52mm of precipitation.