Click on a day for an hourly weather forecast
The temperatures in Windsor in September are usually low and can range between 10°C and 16°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 | 7° / 3° | 11 | 17 | 4 | 105 mm | Awful | Windsor in January |
| February | 7° / 3° | 11 | 13 | 5 | 113 mm | Awful | Windsor in February |
| March | 9° / 3° | 10 | 19 | 2 | 99 mm | Awful | Windsor in March |
| April | 11° / 5° | 7 | 22 | 1 | 82 mm | Bad | Windsor in April |
| May | 14° / 7° | 8 | 23 | 0 | 97 mm | Ok | Windsor in May |
| June | 16° / 10° | 8 | 22 | 0 | 121 mm | Ok | Windsor in June |
| July | 17° / 11° | 9 | 22 | 0 | 130 mm | Ok | Windsor in July |
| August | 17° / 11° | 10 | 21 | 0 | 149 mm | Ok | Windsor in August |
| September | 16° / 10° | 7 | 23 | 0 | 99 mm | Ok | Windsor in September |
| October | 13° / 8° | 10 | 21 | 0 | 132 mm | Bad | Windsor in October |
| November | 9° / 6° | 9 | 20 | 1 | 123 mm | Bad | Windsor in November |
| December | 7° / 4° | 9 | 20 | 2 | 110 mm | Awful | Windsor in December |