Mariehamn weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Excellent
Best time to visit: June – August
What is the weather like in Mariehamn in August?
In August, Mariehamn is mild: daytime highs average 18 °C, and nights cool down to about 16 °C. The sea averages 16.9 °C – swimming is only for the hardy. The sun shines for around 9 hours a day. Rain is frequent, with about 10 rainy days and 55 mm in total. All in all, August is an excellent month for a holiday in Mariehamn.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 89 | 86 | 63 |
| Day | 19° | 18° | 15° |
| Night | 15° | 16° | 12° |
| Sea | 16° | 17° | 14° |
| Sun | 10 h | 9 h | 6 h |
| Rain days | 9 | 10 | 9 |
More details for August
- Daylight
- 15 h 46 min05:52 – 21:38
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 1 daydew point 18 °C or moreAll months
- Wind
- 22 km/haverage daily peakAll months
- Cloud cover
- 57 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC+3Europe/Mariehamn
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %98 %
- Few rainy daysweight 30 %56 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
- Rain jacket or umbrella
Mariehamn in August: quick answers
Is Mariehamn hot in August?
No. In August, Mariehamn is mild: daytime highs average 18 °C and nights drop to about 16 °C.
Can you swim in Mariehamn in August?
Only if you don't mind cold water: in August the sea averages just 16.9 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Mariehamn in August?
Rain is frequent, with about 10 rainy days and 55 mm in total.
Mariehamn month by month
The whole year in MariehamnAll destinations: Åland IslandsWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences