The climate in Mississauga during September can be summarized as mild and reasonably dry.
September is in the fall / autumn in Mississauga and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (69°F), whilst at night 11°C (51°F) is normal.
| Daytime temperature | 20.8°C 69.4°F |
|---|---|
| Nightly temperature | 10.8°C 51.4°F |
| Average temperature | 15.8°C 60.4°F |
| Daily sunshine | 6.4 hrs |
| Avg rainfall | 71 mm 2.8 ins |
| Rainy days | 9 days |
| Sea temperature | 19.1°C 66.4°F |
| Humidity | 76% |
| Windspeed | 12.2kph 8 mph |
On average September is the 3rd wettest month of the year in Mississauga with around 71mm 2.8 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.
On the flip side this corresponds to an average of 6.4 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 Mississauga in September 2025.
Best places to visit in September
| Hottest month: | July | 26°C 78.8°F |
|---|---|---|
| Driest month: | February | 46mm 1.8ins |
| Sunniest month: | July | 9.9hrs |
| Coldest month: | January | -1.7°C 28.9°F |
| Wettest month: | August | 82mm 3.2ins |