Last updated: March 2, 2024
The weather in Mariehamn, Åland Islands, during September is characterized by an average temperature of 14°C (57°F). Highs can soar to 18°C (64°F), while lows may dip to 9°C (49°F). Typically, the humidity level in Mariehamn throughout September hovers around 85%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, Mariehamn averages 56 mm (2.2 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 12 hours 47 minutes of daylight, with the sun shining for approximately 10 hours 35 minutes each day. Additionally, there is a 31% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In September, the UV Index in Mariehamn reaches a maximum of 4, indicating a level of Moderate exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 30 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 1 | 2 | 3 | 3 | 4 | 4 | 3 | 3 | 2 | 1 | 1 |
| Exposure | Low | Moderate | Low | ||||||||||
| Time to burn | 45 min | 30 min | 45 min | ||||||||||