The climate in Calgary during September can be summarized as mild and reasonably dry.
September is in the fall / autumn in Calgary and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 17°C (63°F), whilst at night 4°C (39°F) is normal.
| Daytime temperature | 17.2°C 63°F |
|---|---|
| Nightly temperature | 3.8°C 38.8°F |
| Average temperature | 10.5°C 50.9°F |
| Daily sunshine | 7.1 hrs |
| Avg rainfall | 44 mm 1.7 ins |
| Rainy days | 8 days |
| Sea temperature | 11.3°C 52.4°F |
| Humidity | 63% |
| Windspeed | 14kph 9 mph |
On average September is the 5th wettest month of the year in Calgary with around 44mm 1.7 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.
On the flip side this corresponds to an average of 7.1 hours of sunshine per day.
The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Calgary in September 2025.
Best places to visit in September
| Hottest month: | July | 22.6°C 72.7°F |
|---|---|---|
| Driest month: | February | 12mm 0.5ins |
| Sunniest month: | July | 10.9hrs |
| Coldest month: | January | -4.9°C 23.2°F |
| Wettest month: | June | 79mm 3.1ins |