Click on a day for an hourly weather forecast
The temperatures in Montreal in September are comfortable with low of 12°C and and high up to 21°C.
You can expect about 3 to 8 days of rain in Montreal 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 Montreal in September 2025.
If you’re planning to visit Montreal in the near future, we highly recommend that you review the 14 day weather forecast for Montreal before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -6° / -13° | 4 | 5 | 21 | 122 mm | Awful | Montreal in January |
| February | -5° / -12° | 5 | 3 | 21 | 128 mm | Awful | Montreal in February |
| March | 1° / -6° | 8 | 8 | 16 | 120 mm | Awful | Montreal in March |
| April | 10° / 2° | 10 | 15 | 6 | 159 mm | Awful | Montreal in April |
| May | 19° / 9° | 10 | 21 | 0 | 172 mm | Ok | Montreal in May |
| June | 23° / 13° | 8 | 22 | 0 | 183 mm | Good | Montreal in June |
| July | 26° / 16° | 8 | 23 | 0 | 157 mm | Good | Montreal in July |
| August | 25° / 16° | 7 | 24 | 0 | 157 mm | Good | Montreal in August |
| September | 21° / 12° | 6 | 24 | 0 | 127 mm | Good | Montreal in September |
| October | 13° / 6° | 9 | 21 | 1 | 167 mm | Bad | Montreal in October |
| November | 5° / 0° | 8 | 15 | 7 | 113 mm | Awful | Montreal in November |
| December | -2° / -7° | 7 | 8 | 16 | 139 mm | Awful | Montreal in December |