Click on a day for an hourly weather forecast
The temperatures in Vaasa in September are usually low and can range between 10°C and 14°C.
You can expect about 3 to 8 days of rain in Vaasa 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 Vaasa in September 2025.
If you’re planning to visit Vaasa in the near future, we highly recommend that you review the 14 day weather forecast for Vaasa before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -6° | 5 | 7 | 20 | 67 mm | Awful | Vaasa in January |
| February | -3° / -7° | 5 | 5 | 19 | 62 mm | Awful | Vaasa in February |
| March | 0° / -5° | 6 | 8 | 17 | 61 mm | Awful | Vaasa in March |
| April | 4° / 0° | 6 | 16 | 9 | 63 mm | Awful | Vaasa in April |
| May | 10° / 5° | 7 | 22 | 2 | 84 mm | Awful | Vaasa in May |
| June | 14° / 9° | 6 | 24 | 0 | 92 mm | Good | Vaasa in June |
| July | 18° / 13° | 7 | 24 | 0 | 112 mm | Ok | Vaasa in July |
| August | 18° / 13° | 9 | 22 | 0 | 135 mm | Ok | Vaasa in August |
| September | 14° / 10° | 7 | 23 | 0 | 91 mm | Ok | Vaasa in September |
| October | 7° / 5° | 9 | 18 | 5 | 107 mm | Awful | Vaasa in October |
| November | 4° / 2° | 10 | 12 | 9 | 91 mm | Awful | Vaasa in November |
| December | 0° / -3° | 8 | 5 | 18 | 81 mm | Awful | Vaasa in December |