Generally the weather in Seinajoki right through September is 8. Through the month the highs are about 15 with lows of 5 degrees celsius. We have put some more info below:
| Month | Degrees Celsius |
|---|---|
| Temperature | 8 |
| High Temperature | 15 |
| Low Temperature | 5 |
Useful Links: Seinajoki Weather: Average Weather & Yearly Climate