News / Edmonton

Alberta’s hot August the ‘new normal’ U of A prof says

Last month was Edmonton’s second hottest August in the past 20 years, and in Calgary conditions were just slightly cooler.

Edmonton’s record-breaking August heat could mean a warmer fall season, a U of A professor says.

Hilary McDonald/For Metro

Edmonton’s record-breaking August heat could mean a warmer fall season, a U of A professor says.

The scorching August temperatures in both Edmonton and Calgary could become a new normal, a University of Alberta professor says.

Last month was Edmonton’s second hottest August in the past 20 years, and in Calgary conditions were just slightly cooler. And the reason, said U of A Earth and Atmospheric Sciences professor Gerhard Reuter, is a province-wide El Nino cycle of light westerly winds coming over the mountains and settling into what we know as a warming Chinook effect.

This might sound a bit scientific, but Albertans certainly felt it — the average daytime high for August is about 22 degrees Celsius, but the average last month was almost 25C in Edmonton, and almost 24C in Calgary.

“The air gets compressed and heats up, and if there are no or few clouds, we get a lot of solar radiation and heating by the sun,” Reuter said.

“That and the combination of those weak winds from the west and the lack of cloud cover together makes for the warm weather.”

Reuter said this trend of hot summers could happen more often. As the Arctic continues to warm with more carbon dioxide released in the air, a greenhouse effect could mean more evaporation and drier conditions.

This warmer weather was felt across Alberta, and the trend could stretch into a warmer than usual fall, he said.

“There are other factors that would pertain to that, but the probability of having a warm fall is higher than usual because of the El Nino,” Reuter said.

Facts:

24.5C: Average August 2015 high daily temperature, Edmonton

23.6C: Average August 2015 high daily temperature, Calgary

22.6C: Edmonton’s 30-year average daily high temperatures in August

22.8C: Calgary’s 30-year average daily high temperatures in August

3: Number of +30C days in August in Edmonton, the most since 1998

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