AI-generatedMariehamn at a glance
- Best time
- Jun – Aug
- Warmest month
- Jul · 19°
- Warmest sea
- Aug · 16.9°
- Sunshine a year
- 2,050 h
- Rain a year
- 495 mm
- Climate
- Maritime
- Time zone
- UTC+2 / UTC+3
- Elevation
- 11 m
Climate in Mariehamn
Mariehamn has a maritime climate with moderate summers and cool, often grey winters. July is the warmest month with average highs of 19 °C, while February is the coolest at 0 °C. With around 2,050 hours of sunshine a year, Mariehamn is moderately sunny; July is the sunniest month with 10.4 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Poor
Best time to visit: June – August
A typical day in October
- Morning, 08:00: about 7°
- Midday, 13:00: about 9°
- Afternoon, 16:00: about 9°
- Evening, 20:00: about 9°
- Night, 23:00: about 8°
08:1718:35
Cold evenings: bring a warm jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:51–09:16 · evening 17:36–19:01
- Blue hour
- Morning 07:35–07:51 · evening 19:01–19:17
Golden hour: the sun between 4° below and 6° above the horizon; blue hour: 6° to 4° below it. Times for the 15th of the month; mountains and clouds shift the light.
What is the weather like in Mariehamn in October?
In October, Mariehamn is cold: daytime highs average 10 °C, and nights cool down to about 7 °C. The sea averages 10.0 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. Rain is frequent, with about 10 rainy days and 52 mm in total. All in all, October is not an ideal month for a holiday in Mariehamn.
More details for October
- Daylight
- 10 h 18 min08:17 – 18:35
- UV index
- 1 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 26 km/haverage daily peakAll months
- Cloud cover
- 70 %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 %15 %
- Sunshineweight 20 %3 %
- 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 October
- Warm jacket
- Rain jacket or umbrella
Sea temperature in Mariehamn
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 9.1 – 11.2 °C
Swimming season: Never above 20 °C
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in Mariehamn ranges from 1.4 °C in February to 16.9 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
The sea warms up slowly: it is warmest in August, while the air already peaks in July. From October to February the sea is even warmer than the afternoon air. The sea temperature varies from year to year: in August, eight out of ten years were between 15.6 and 18.1 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 2.4° | 1.4° | 3.7° | cold |
| FebruaryFeb | 1.4° | 0.0° | 2.2° | cold |
| MarchMar | 1.4° | 0.3° | 2.5° | cold |
| AprilApr | 2.7° | 1.5° | 3.8° | cold |
| MayMay | 5.8° | 5.0° | 6.6° | cold |
| JuneJun | 10.9° | 9.3° | 13.1° | cold |
| JulyJul | 15.9° | 14.3° | 17.1° | cold |
| AugustAug | 16.9° | 15.6° | 18.1° | cold |
| SeptemberSep | 14.0° | 12.8° | 15.1° | cold |
| OctoberOct | 10.0° | 9.1° | 11.2° | cold |
| NovemberNov | 6.9° | 5.7° | 8.0° | cold |
| DecemberDec | 4.3° | 3.2° | 5.4° | cold |
Sunshine hours in Mariehamn
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 3.2 of 10.3 hours of daylight in Mariehamn, 31 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in Mariehamn
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 1 · lowLittle protection needed; sunglasses on bright days.
The sun is strongest in June (UV 6).
Minutes until sunburn in October
- Very fair skin
- over 2 h
- Fair skin
- over 2 h
- Light brown skin
- over 2 h
- Olive skin
- over 2 h
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in Mariehamn: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, Mariehamn has about 10 rainy days with 52 mm of rain in total.
Wind and clouds in Mariehamn
How breezy and how cloudy Mariehamn is through the year. Tap a month to select it on the whole page.
Wind
Typical daily peak of the wind in km/h: what the afternoon breeze usually reaches, not the gusts.
In October, the wind in Mariehamn typically peaks at 26 km/h during the day: Beaufort 4, moderate breeze.
Breezy months for windsurfing and kiting
From Beaufort 4 (20 km/h) the daily breeze is usually enough for windsurfing and often for kiting, and here it gets there all year.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 70 % of the sky over Mariehamn: mostly cloudy, with about 3.2 hours of sunshine a day.
Wind: mean daily maximum of the hourly wind 10 m above ground (ERA5, 1996–2025). Gusts are stronger, and the model grid of about 28 km smooths out local effects such as capes and valley winds. Clouds: mean total cloud cover of all layers over day and night (ERA5, 1996–2025). Thin high cloud counts as cover even when the sun still shines through.
Snow in Mariehamn
Snow is possible in Mariehamn, but no month makes it likely: the chance of seeing snow during a week's stay, the days with fresh snow and how much falls. Tap a month to select it.
Snow calendar
- hardly any
- possible
- likely
- very likely
In October, it hardly ever snows in Mariehamn.
Snow days bring at least 1 cm of fresh snow. Fresh snow comes from ERA5 snowfall (1996–2025) at the height of the place, not on the slopes above it; the snow chance also weighs whether the snow settles. An estimate from climate averages, not a snow report.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Mariehamn
How warm the nights get in each month, from the mean night-time low. Tap a month for details.
- Frost below 0°
- Cold 0–8°
- Cool 8–15°
- Pleasant 15–20°
ColdOctober: nights around 7°. The room should be heated.
The coolest nights are in February (−3°), the warmest in August (16°). Nights are pleasant for sleeping (15 to 20 °C) from July to August. Nights fall below 8 °C on average from October to May, so the room should be heated.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sea | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|---|
| JanuaryJan | 19 | 1° | −2° | 2.4° | 1.2 h | 9 | 39 |
| FebruaryFeb | 22 | 0° | −3° | 1.4° | 2.4 h | 8 | 29 |
| MarchMar | 30 | 2° | −1° | 1.4° | 4.8 h | 7 | 26 |
| AprilApr | 39 | 5° | 2° | 2.7° | 7.7 h | 7 | 27 |
| MayMay | 53 | 10° | 6° | 5.8° | 9.9 h | 7 | 34 |
| JuneJun | 76 | 15° | 11° | 10.9° | 10.3 h | 8 | 45 |
| JulyJul | 89 | 19° | 15° | 15.9° | 10.4 h | 9 | 53 |
| AugustAug | 86 | 18° | 16° | 16.9° | 8.9 h | 10 | 55 |
| SeptemberSep | 63 | 15° | 12° | 14.0° | 6.1 h | 9 | 44 |
| OctoberOct | 25 | 10° | 7° | 10.0° | 3.2 h | 10 | 52 |
| NovemberNov | 17 | 6° | 4° | 6.9° | 1.3 h | 10 | 47 |
| DecemberDec | 14 | 3° | 0° | 4.3° | 0.9 h | 11 | 46 |
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
60.10° N, 19.93° E · 11 m · Europe/Mariehamn
Best time to visit Mariehamn
The best time to visit Mariehamn is from June to August. The sea stays too cool for a classic beach holiday: even in August it only reaches 16.9 °C. For sightseeing, day trips and hiking, conditions are most comfortable from July to August. The wettest month is August with 55 mm of precipitation.
Mariehamn through the seasons
How the weather changes over the seasons, with averages for each.
Mariehamn in spring
Mar – May
Fair
- 2–10 °C by day
- Sea 3 °C
- 8 h of sun a day
- 21 rainy days in all
Mariehamn in summer
Jun – Aug
Excellent
- 15–19 °C by day
- Sea 15 °C
- 10 h of sun a day
- 27 rainy days in all
Mariehamn in autumn
Sep – Nov
Poor
- 6–15 °C by day
- Sea 10 °C
- 4 h of sun a day
- 29 rainy days in all
Mariehamn in winter
Dec – Feb
Poor
- 0–3 °C by day
- Sea 3 °C
- 2 h of sun a day
- 28 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in Mariehamn for you.
Your best months: July – August
Based on the climate averages; tap a month to see its details.
Compare two months in Mariehamn
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
July has the better holiday weather in Mariehamn: score 89 against 25. In July, days are 9 °C warmer than in October. The sea is 6 °C warmer in July. July has one rainy day fewer. The sun shines 7 hours longer a day in July.
| Month | October | July |
|---|---|---|
| Weather score | 25 | 89better |
| Day high | 10° | 19° |
| Night low | 7° | 15° |
| Sea | 10.0° | 15.9° |
| Sunshine | 3.2 h | 10.4 hbetter |
| Rainy days | 10 | 9better |
| Rainfall | 52 mm | 53 mm |
| Muggy days | 0better | 1 |
Based on the climate averages 1996–2025.
Which month for what?
Beach & swimming
No month
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
Jul – Aug
15–28 °C and not too much rain
Snow
Nov – Mar
Snow on 2 or more days
Mariehamn month by month
The typical weather for every month at a glance.
19January1° · Sea 2° · 1 h
In January, Mariehamn is freezing cold: daytime highs average 1 °C, and nights often drop below freezing (−2 °C). The sea averages 2.4 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. Precipitation, often as snow, falls on about 9 days, totalling 39 mm. Snow falls on about 5 days. It is often windy, with gusts of around 28 km/h. All in all, January is not an ideal month for a holiday in Mariehamn.
Mariehamn in January22February0° · Sea 1° · 2 h
In February, Mariehamn is freezing cold: daytime highs average 0 °C, and nights often drop below freezing (−3 °C). The sea averages 1.4 °C – swimming is only for the hardy. The sun is scarce, with only about 2 hours a day. Precipitation, often as snow, falls on about 8 days, totalling 29 mm. Snow falls on about 5 days. All in all, February is not an ideal month for a holiday in Mariehamn.
Mariehamn in February30March2° · Sea 1° · 5 h
In March, Mariehamn is freezing cold: daytime highs average 2 °C, and nights often drop below freezing (−1 °C). The sea averages 1.4 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Precipitation, often as snow, falls on about 7 days, totalling 26 mm. Snow falls on about 4 days. All in all, March is not an ideal month for a holiday in Mariehamn.
Mariehamn in March39April5° · Sea 3° · 8 h
In April, Mariehamn is cold: daytime highs average 5 °C, and nights cool down to about 2 °C. The sea averages 2.7 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain falls on about 7 days, adding up to 27 mm. All in all, April is not an ideal month for a holiday in Mariehamn.
Mariehamn in April53May10° · Sea 6° · 10 h
In May, Mariehamn is cold: daytime highs average 10 °C, and nights cool down to about 6 °C. The sea averages 5.8 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. Rain falls on about 7 days, adding up to 34 mm. All in all, May is a so-so month for a holiday in Mariehamn.
Mariehamn in May76June15° · Sea 11° · 10 h
In June, Mariehamn is cool: daytime highs average 15 °C, and nights cool down to about 11 °C. The sea averages 10.9 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. Rain falls on about 8 days, adding up to 45 mm. All in all, June is a good month for a holiday in Mariehamn.
Mariehamn in June89July19° · Sea 16° · 10 h
In July, Mariehamn is mild: daytime highs average 19 °C, and nights cool down to about 15 °C. The sea averages 15.9 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. Rain is frequent, with about 9 rainy days and 53 mm in total. All in all, July is an excellent month for a holiday in Mariehamn.
Mariehamn in July86August18° · Sea 17° · 9 h
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.
Mariehamn in August63September15° · Sea 14° · 6 h
In September, Mariehamn is cool: daytime highs average 15 °C, and nights cool down to about 12 °C. The sea averages 14.0 °C – swimming is only for the hardy. Expect around 6 hours of sunshine a day. Rain falls on about 9 days, adding up to 44 mm. All in all, September is a good month for a holiday in Mariehamn.
Mariehamn in September25October10° · Sea 10° · 3 h
In October, Mariehamn is cold: daytime highs average 10 °C, and nights cool down to about 7 °C. The sea averages 10.0 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. Rain is frequent, with about 10 rainy days and 52 mm in total. All in all, October is not an ideal month for a holiday in Mariehamn.
Mariehamn in October17November6° · Sea 7° · 1 h
In November, Mariehamn is cold: daytime highs average 6 °C, and nights cool down to about 4 °C. The sea averages 6.9 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. Rain is frequent, with about 10 rainy days and 47 mm in total. Snow falls on about 2 days. All in all, November is not an ideal month for a holiday in Mariehamn.
Mariehamn in November14December3° · Sea 4° · 1 h
In December, Mariehamn is freezing cold: daytime highs average 3 °C, and nights cool down to about 0 °C. The sea averages 4.3 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. Precipitation, often as snow, falls on about 11 days, totalling 46 mm. Snow falls on about 4 days. All in all, December is not an ideal month for a holiday in Mariehamn.
Mariehamn in DecemberMariehamn compared
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Mariehamn vs. Uppsala
In October the holiday weather in Mariehamn and Uppsala is about equally good (score 25 vs. 25). During the day Uppsala is 1 °C cooler than Mariehamn.
| in October | Mariehamn | Uppsala |
|---|---|---|
| Holiday score | 25 | 25 |
| Daytime high | 10° | 9° |
| Sea | 10° | – |
| Sunshine | 3 h | 3 h |
| Rainy days | 10 | 9 |
| Best time | Jun – Aug | May – Sep |
Through the year
Planning a trip to Mariehamn
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Mariehamn in the school holidays
How the weather suits the usual holiday periods. Dates vary by school and region, so each holiday uses the months it usually falls in.
Mariehamn has its best school-holiday weather during the summer holidays (score 87) and its weakest during the Christmas holidays (score 17).
- 36
Easter holidays
Mar – Apr
Poor
- 4 °C by day
- Sea 2 °C
- 6.8 h of sun a day
- 7 rainy days a month
Keep in mind: Snow
- 58
May half-term
May – Jun
Fair
- 11 °C by day
- Sea 7 °C
- 10.0 h of sun a day
- 7 rainy days a month
- 87
Summer holidays
Jul – Aug
ExcellentBest holidays
- 18 °C by day
- Sea 17 °C
- 9.4 h of sun a day
- 10 rainy days a month
Good for: Sightseeing & walks
- 25
October half-term
Oct
Poor
- 10 °C by day
- Sea 10 °C
- 3.2 h of sun a day
- 10 rainy days a month
- 17
Christmas holidays
Dec – Jan
Poor
- 2 °C by day
- Sea 3 °C
- 1.1 h of sun a day
- 10 rainy days a month
Keep in mind: Snow
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- about 2 h 25 min
- Distance
- 1,580 km
- Time zone
- UTC+3
- Jet lag
- Hardly any (under 3 h)
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about Mariehamn
When is the best time to visit Mariehamn?
The best time to visit Mariehamn is from June to August. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in Mariehamn?
The sea temperature in Mariehamn ranges from 1.4 °C in February to 16.9 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
Can you swim in Mariehamn in October?
Only if you don't mind cold water: in October the sea averages just 10.0 °C. Comfortable swimming temperatures are not reached at any time of year.
What is the warmest month in Mariehamn?
July is the warmest month, with average highs of 19 °C and nights around 15 °C. February is the coolest month at 0 °C.
When does it rain most in Mariehamn?
The wettest month is August with 55 mm of precipitation. The driest month is March with 26 mm.
How many hours of sunshine does Mariehamn get?
Mariehamn gets around 2,050 hours of sunshine a year. The sunniest month is July with 10.4 hours a day; in December there are 0.9 hours a day.
What time zone is Mariehamn in?
Mariehamn uses the time zone Europe/Mariehamn: UTC+2 in January and UTC+3 in July.
How long is the flight from London to Mariehamn?
A nonstop flight from London to Mariehamn takes about 2 h 25 min, for a straight-line distance of about 1,580 km.
Which school holidays are best for Mariehamn?
Mariehamn has its best school-holiday weather during the summer holidays (score 87) and its weakest during the Christmas holidays (score 17). Holiday ratings (0–100): Easter holidays 36, May half-term 58, Summer holidays 87, October half-term 25, Christmas holidays 17.
Near Mariehamn
Other destinations close by.
Places with a climate like Mariehamn
Destinations whose weather through the year is closest to Mariehamn's – good alternatives.