Mariehamn in September
6.6out of 10
Possible, with caveats
Cool: highs only around 14°C. Frequent rain: about 9 rainy days.
14°CAvg high
12°CAvg low
9Rainy days (54 mm)
12:31 hDaylight
07:19Sunrise · 19:50 Sunset
Why this score
- Cool: highs only around 14°C
- Frequent rain: about 9 rainy days
- Rain varies a lot between years (±4.5 days)
What to wear and pack
- Layers you can add or remove
- Rain jacket or compact umbrella
How reliable is the forecast?
Rain in September varies a lot between years (±4.5 rainy days), so check the forecast closer to your trip. Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 1°C | -1°C | 43 mm | 11 | – | – | 4.2 |
| February | 0°C | -2°C | 29 mm | 8 | – | – | 4.2 |
| March | 1°C | -1°C | 28 mm | 7 | – | – | 4.5 |
| April | 4°C | 2°C | 29 mm | 7 | – | – | 5.2 |
| May | 8°C | 6°C | 33 mm | 7 | – | – | 6.0 |
| June | 13°C | 11°C | 48 mm | 8 | – | – | 6.6 |
| July | 17°C | 15°C | 48 mm | 8 | – | – | 7.3 |
| August | 18°C | 16°C | 55 mm | 10 | – | – | 7.0 |
| September | 14°C | 12°C | 54 mm | 9 | – | – | 6.6 |
| October | 9°C | 8°C | 62 mm | 12 | – | – | 5.5 |
| November | 6°C | 4°C | 60 mm | 13 | – | – | 4.8 |
| December | 3°C | 1°C | 56 mm | 13 | – | – | 4.2 |
Frequently asked questions
How hot is Mariehamn in September?
Daytime highs average 14°C and nights about 12°C.
When is the best time to visit Mariehamn?
The best months are July, August.