Climate averages 1991–2020
Mariehamn weather
in May.
A cool, fairly dry month: the 5th warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a cool month in Mariehamn: daytime highs average 9.7°C and nights cool to about 6.1°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 33 mm of rain on roughly 7 days, which makes May a fairly dry month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 17 h 08 min on an average May day.
The nearest other city in this atlas is Uppsala (130 km away). In May its highs average 15.2°C, 5.5°C warmer than Mariehamn, with 46 mm of rain.
From May to June, average highs rise by 4.8°C to 14.5°C, and monthly rainfall rises from 33 mm to 49 mm.
The annual picture
May in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Mariehamn climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.0°C-1.6°C | -1.6°C | 43 | 10.5 | 6.87 h |
| February | -0.2°C-2.9°C | -2.9°C | 29 | 7.8 | 9.19 h |
| March | 1.5°C-1.5°C | -1.5°C | 27 | 7.1 | 11.712 h |
| April | 5.2°C1.8°C | 1.8°C | 29 | 6.9 | 14.515 h |
| May, selected | 9.7°C6.1°C | 6.1°C | 33 | 6.6 | 17.117 h |
| June | 14.5°C10.9°C | 10.9°C | 49 | 7.5 | 18.719 h |
| July | 18.4°C15.1°C | 15.1°C | 48 | 7.6 | 18.018 h |
| August | 18.3°C15.4°C | 15.4°C | 55 | 10.2 | 15.716 h |
| September | 14.3°C11.8°C | 11.8°C | 54 | 9.2 | 13.013 h |
| October | 9.1°C7.0°C | 7.0°C | 62 | 11.8 | 10.210 h |
| November | 5.3°C3.2°C | 3.2°C | 60 | 13.0 | 7.68 h |
| December | 2.8°C0.4°C | 0.4°C | 56 | 13.0 | 6.06 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- Uppsala in MaySweden · 130 kmHigh 15.2°C · Low 6.0°C · 46 mm rain
- Sollentuna in MaySweden · 134 kmHigh 14.7°C · Low 6.5°C · 44 mm rain
- Turku in MayFinland · 135 kmHigh 14.4°C · Low 5.4°C · 41 mm rain
- Stockholm in MaySweden · 135 kmHigh 13.8°C · Low 6.7°C · 42 mm rain
- Haninge in MaySweden · 144 kmHigh 13.1°C · Low 6.5°C · 39 mm rain
- Huddinge in MaySweden · 146 kmHigh 13.9°C · Low 6.7°C · 42 mm rain
- Södertälje in MaySweden · 164 kmHigh 15.5°C · Low 6.6°C · 44 mm rain
- Gävle in MaySweden · 166 kmHigh 14.9°C · Low 5.9°C · 44 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Mariehamn) is explained once on the Mariehamn year overview and on the Sources, method and limits page.