Well, it took me a bit longer than expected to go through all the weather data for the summer, and to tell the truth, I could possibly dig into a few more details, but sometimes you have to know when to stop researching and publish what you found.
The hardest part, besides spending all the time going through the data and then comparing it to historical values, was trying to figure out the easiest way to summarize it. After creating several Excel spreadsheets, worth of data and calculations, I have summarized all the data into one table. The table below represents all the data I felt relevant and not too time consuming to locate and analyze, for the three months of summer (June, July, August). Temperatures in the table are in degrees Celsius and precipitation is in millimetres. Top rankings in each category are highlighted in red, except for precipitation. For that data, I highlighted the highest amounts in blue and the lowest in red, since the big story of the summer was not all the rain that fell, but rather the lack of rainfall.
Before taking a closer look at the data, I must comment on Edmonton. The usual data station that I use (Edmonton International CS) must have had some trouble this summer as there were a fair number of missing days. So, I switched to the alternate station at that location, which is the Edmonton International Airport. Before I discovered the missing data, my original data for this study was coming from Edmonton Blatchford. It seems you get different data depending on where you click on Environment Canada’s website. I am not sure why there are so many different Environment Canada stations for Edmonton (eight stations with data in 2021). To compare with historical records, I chose the airport location since it has the longest dataset. If I had kept the Blatchford station, then the numbers would have been much higher for Edmonton.
Starting off with the number of days above 30 and 35 C: For 30-plus C days, Winnipeg recorded the most, but Calgary and Peace River had the largest deviation from average with over 14 more 30-plus C days than normal. Looking at the number of 35-plus C days, Saskatoon had the most, with five, with Winnipeg and Brandon coming in at four days. This might not seem like much, but if you look at the difference from average, you will see that on average we just don’t see temperatures this hot. Most locations in Manitoba and Saskatchewan only expect to see one day per year above 35 C. In Alberta, both Calgary and Peace River almost never see temperatures above 35 C, with Edmonton seeing one once every year or two.
The maximum summer temperatures across the Prairies were very warm, with an impressive 40 C in Saskatoon. The coldest temperatures, or minimum temperatures in the summer, were not surprisingly cool. Don’t forget that June is part of the summer, and it began on the cool side before the heat finally moved in. It is also not surprising that Peace River had the coolest temperature, simply due to its more northerly location, but it also had the second-warmest temperature of the summer.
Looking at mean summer temperatures or the average temperature over the whole summer, Winnipeg was the warmest, which is not surprising given the city’s geographical location. The more meaningful statistic is the difference from the mean, and for this value Calgary was the warmest compared to average, with the mean summer temperature coming in at 17.7 C. This was 2.4 C warmer than average. Looking back at Calgary’s records, going back to 1894, it appears the summer of 2021 was the warmest summer on record, just beating out the previous record which was 17.6 C set back in 1961.
Just looking at temperatures, Winnipeg was the overall warmest place on the Prairies, with three top temperature readings. Saskatoon was the hottest place, if that makes sense, with three top readings all related to extreme heat. Finally, Calgary was the warmest place compared to average.
Wettest and driest
We will now take a look at precipitation to wrap up our deep dive into the summer weather of 2021. Brandon was the “wet” spot, coming in with about 295 mm of rain which was about 75 mm above average. For those of you out west, or who missed my articles on drought and summer rains over the last few years, this rainfall in the Brandon region is not surprising. This region seems to consistently receive shots of heavy summer rain year after year. The dry spot was Saskatoon, coming in just shy of 100 mm. Compared to average, Edmonton was the driest spot, with a summer rainfall deficit of nearly 93 mm. Winnipeg, Calgary and Peace River all experienced precipitation deficits of over 60 mm and were also quite dry.
The stats confirm what we all already knew; it was a hot summer. What might be a little surprising was just how many really hot days there were, at least compared to average.