Click on a day for an hourly weather forecast
The temperatures in Windsor 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 Windsor 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 Windsor in September 2025.
If you’re planning to visit Windsor in the near future, we highly recommend that you review the 14 day weather forecast for Windsor before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -7° | 5 | 9 | 17 | 74 mm | Awful | Windsor in January |
| February | -1° / -6° | 5 | 8 | 16 | 76 mm | Awful | Windsor in February |
| March | 5° / -1° | 7 | 16 | 8 | 86 mm | Awful | Windsor in March |
| April | 11° / 4° | 10 | 17 | 3 | 161 mm | Awful | Windsor in April |
| May | 18° / 10° | 9 | 22 | 0 | 193 mm | Ok | Windsor in May |
| June | 23° / 16° | 9 | 21 | 0 | 209 mm | Good | Windsor in June |
| July | 26° / 19° | 9 | 22 | 0 | 178 mm | Good | Windsor in July |
| August | 26° / 19° | 7 | 24 | 0 | 162 mm | Good | Windsor in August |
| September | 22° / 15° | 7 | 23 | 0 | 122 mm | Ok | Windsor in September |
| October | 15° / 9° | 7 | 24 | 0 | 116 mm | Ok | Windsor in October |
| November | 8° / 3° | 6 | 19 | 5 | 78 mm | Bad | Windsor in November |
| December | 2° / -2° | 7 | 12 | 13 | 71 mm | Awful | Windsor in December |