Click on a day for an hourly weather forecast
The temperatures in Bay City in September are comfortable with low of 12°C and and high up to 22°C.
You can expect about 3 to 8 days of rain in Bay City 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 Bay City in September 2025.
If you’re planning to visit Bay City in the near future, we highly recommend that you review the 14 day weather forecast for Bay City before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -9° | 5 | 6 | 21 | 75 mm | Awful | Bay City in January |
| February | -2° / -8° | 3 | 6 | 19 | 70 mm | Awful | Bay City in February |
| March | 5° / -3° | 7 | 13 | 12 | 77 mm | Awful | Bay City in March |
| April | 11° / 2° | 9 | 16 | 5 | 115 mm | Awful | Bay City in April |
| May | 18° / 9° | 7 | 23 | 0 | 115 mm | Ok | Bay City in May |
| June | 23° / 13° | 7 | 23 | 0 | 139 mm | Good | Bay City in June |
| July | 26° / 16° | 7 | 24 | 0 | 118 mm | Good | Bay City in July |
| August | 25° / 15° | 6 | 25 | 0 | 120 mm | Perfect | Bay City in August |
| September | 22° / 12° | 5 | 25 | 0 | 81 mm | Good | Bay City in September |
| October | 14° / 7° | 7 | 24 | 0 | 101 mm | Ok | Bay City in October |
| November | 7° / 1° | 6 | 15 | 9 | 65 mm | Bad | Bay City in November |
| December | 1° / -4° | 6 | 9 | 17 | 62 mm | Awful | Bay City in December |