Click on a day for an hourly weather forecast
The temperatures in Green Bay in September are comfortable with low of 11°C and and high up to 21°C.
You can expect about 3 to 8 days of rain in Green Bay 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 Green Bay in September 2025.
If you’re planning to visit Green Bay in the near future, we highly recommend that you review the 14 day weather forecast for Green Bay before you arrive.
Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
---|---|---|---|---|---|---|---|
January | -6° / -11° | 3 | 9 | 18 | 55 mm | Awful | Green Bay in January |
February | -4° / -10° | 3 | 8 | 17 | 61 mm | Awful | Green Bay in February |
March | 4° / -3° | 6 | 13 | 11 | 83 mm | Awful | Green Bay in March |
April | 10° / 2° | 9 | 15 | 6 | 129 mm | Awful | Green Bay in April |
May | 17° / 8° | 8 | 22 | 0 | 148 mm | Ok | Green Bay in May |
June | 22° / 13° | 7 | 23 | 0 | 160 mm | Ok | Green Bay in June |
July | 26° / 16° | 7 | 24 | 0 | 136 mm | Good | Green Bay in July |
August | 25° / 15° | 5 | 26 | 0 | 108 mm | Perfect | Green Bay in August |
September | 21° / 11° | 5 | 25 | 0 | 85 mm | Good | Green Bay in September |
October | 13° / 6° | 7 | 23 | 2 | 111 mm | Awful | Green Bay in October |
November | 6° / -1° | 5 | 18 | 6 | 82 mm | Awful | Green Bay in November |
December | -2° / -6° | 4 | 11 | 16 | 78 mm | Awful | Green Bay in December |