Click on a day for an hourly weather forecast
The temperatures in Wisconsin in September are comfortable with low of 15°C and and high up to 21°C.
You can expect about 3 to 8 days of rain in Wisconsin 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 Wisconsin in September 2025.
If you’re planning to visit Wisconsin in the near future, we highly recommend that you review the 14 day weather forecast for Wisconsin before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -8° | 5 | 9 | 17 | 49 mm | Awful | Wisconsin in January |
| February | -2° / -7° | 4 | 10 | 15 | 48 mm | Awful | Wisconsin in February |
| March | 4° / -1° | 6 | 17 | 8 | 60 mm | Awful | Wisconsin in March |
| April | 9° / 3° | 7 | 19 | 4 | 109 mm | Awful | Wisconsin in April |
| May | 15° / 9° | 7 | 24 | 0 | 118 mm | Ok | Wisconsin in May |
| June | 21° / 14° | 6 | 24 | 0 | 138 mm | Good | Wisconsin in June |
| July | 24° / 19° | 6 | 25 | 0 | 140 mm | Perfect | Wisconsin in July |
| August | 25° / 18° | 5 | 26 | 0 | 120 mm | Perfect | Wisconsin in August |
| September | 21° / 15° | 5 | 25 | 0 | 87 mm | Good | Wisconsin in September |
| October | 14° / 9° | 6 | 24 | 1 | 97 mm | Good | Wisconsin in October |
| November | 7° / 2° | 5 | 19 | 6 | 52 mm | Bad | Wisconsin in November |
| December | 1° / -3° | 5 | 13 | 13 | 48 mm | Awful | Wisconsin in December |