The Weather Network says it was a particularly hot September in several Alberta communities. (Photo: Marianvejcik | Dreamstime.com)

By David Opinko

September hotter than entire summer average across much of Alberta

Oct 2, 2025 | 9:20 AM

Although September marks the beginning of fall, one weather agency says it was actually hotter than the rest of the summer.

The Weather Network says much of Alberta was hit by a heat wave this past month, breaking long-standing heat records in several communities.

They say that the average temperature in September, including all times of the day, was higher than the averages for June, July and August.

Lethbridge, Calgary, Red Deer and Edmonton were all among the cities that experienced higher temperatures in September than in the rest of the summer.

Average Temperatures in Alberta Cities, Sept. vs June-Aug. 2025. (Image compiled by Pattison Media. Source: The Weather Network)

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It was the hottest September on record in Banff and Edmonton.

Communities including Medicine Hat, Banff and Grande Prairie, on the other hand, were all a bit cooler in September than their summer averages.

It was also the driest September in over a century in Calgary, Edmonton and Medicine Hat.

Calgary received 0.4 mm of rain, making it the driest September since 1885.

Edmonton had 0.1 mm of rain, its driest September since 1888.

Medicine Hat actually received no rain at all, tying it with both 1908 and 1920.

As of October 1, The Weather Network is forecasting a “classic fall setup” across Alberta over the next 10 days. They say an upper-level trough will usher in cooler temperatures in the first week of the month.

Temperatures will return to above-seasonal norms after that.

Precipitation is harder to forecast, so no estimates were provided on that.