Click on a day for an hourly weather forecast
The temperatures in Mississauga in September are comfortable with low of 15°C and and high up to 22°C.
You can expect about 3 to 8 days of rain in Mississauga during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Mississauga in September 2025.
If you’re planning to visit Mississauga in the near future, we highly recommend that you review the 14 day weather forecast for Mississauga before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -7° | 6 | 5 | 20 | 103 mm | Awful | Mississauga in January |
| February | -1° / -7° | 6 | 4 | 19 | 115 mm | Awful | Mississauga in February |
| March | 5° / -2° | 9 | 10 | 12 | 114 mm | Awful | Mississauga in March |
| April | 11° / 3° | 10 | 14 | 6 | 144 mm | Awful | Mississauga in April |
| May | 18° / 9° | 7 | 23 | 0 | 141 mm | Ok | Mississauga in May |
| June | 23° / 14° | 7 | 23 | 0 | 160 mm | Good | Mississauga in June |
| July | 26° / 18° | 9 | 22 | 0 | 168 mm | Good | Mississauga in July |
| August | 26° / 18° | 8 | 23 | 0 | 163 mm | Good | Mississauga in August |
| September | 22° / 15° | 6 | 24 | 0 | 118 mm | Good | Mississauga in September |
| October | 15° / 9° | 9 | 21 | 1 | 145 mm | Ok | Mississauga in October |
| November | 8° / 3° | 7 | 15 | 8 | 103 mm | Awful | Mississauga in November |
| December | 2° / -2° | 8 | 8 | 16 | 112 mm | Awful | Mississauga in December |