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The temperatures in Southern Finland in September are usually low and can range between 12°C and 15°C.
You can expect about 3 to 8 days of rain in Southern Finland 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 Southern Finland in September 2025.
If you’re planning to visit Southern Finland in the near future, we highly recommend that you review the 14 day weather forecast for Southern Finland before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -5° | 4 | 8 | 19 | 60 mm | Awful | Southern Finland in January |
| February | -2° / -5° | 4 | 7 | 17 | 51 mm | Awful | Southern Finland in February |
| March | 1° / -3° | 7 | 10 | 15 | 46 mm | Awful | Southern Finland in March |
| April | 5° / 2° | 6 | 18 | 6 | 42 mm | Awful | Southern Finland in April |
| May | 11° / 7° | 5 | 25 | 1 | 60 mm | Ok | Southern Finland in May |
| June | 16° / 12° | 6 | 24 | 0 | 83 mm | Good | Southern Finland in June |
| July | 20° / 16° | 6 | 25 | 0 | 106 mm | Good | Southern Finland in July |
| August | 19° / 15° | 7 | 24 | 0 | 135 mm | Ok | Southern Finland in August |
| September | 15° / 12° | 6 | 24 | 0 | 91 mm | Good | Southern Finland in September |
| October | 9° / 6° | 8 | 20 | 3 | 90 mm | Awful | Southern Finland in October |
| November | 5° / 3° | 7 | 18 | 5 | 76 mm | Awful | Southern Finland in November |
| December | 1° / -1° | 7 | 11 | 14 | 72 mm | Awful | Southern Finland in December |
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