Sea temperature in Finland
Live water temperatures and swimming conditions across 10 beaches on the Finland coast.
Best time to swim in Finland
The sea in Finland peaks in August, when the water averages around 17°C.
On average, 0 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Outside peak season the water drops toward 6°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.
The coldest month is typically February at around 3°C, when cold-water swimmers dominate the coast.
Finland sea temperature history
Long-term climatology for Finland shows an annual mean sea temperature of 9°C, ranging from 3°C in winter to 17°C at the summer peak.
The seasonal swing is roughly 14°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Finland, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Values are area averages; individual beaches vary by exposure and depth.
Finland sea temperature: frequently asked questions
What is the warmest month to swim in Finland?
August is the warmest month in Finland, when the sea averages about 17°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Finland?
The coldest month in Finland is typically February, when the water averages around 3°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Finland without a wetsuit?
The sea in Finland rarely climbs above 20°C, so a wetsuit is recommended year-round for anything longer than a quick dip.
Do I need a wetsuit in Finland?
Outside peak summer the water in Finland drops toward 6°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Finland?
The long-term annual mean sea temperature in Finland is about 9°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Finland?
The live reading at the top of this page shows the current sea temperature in Finland, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Warmest beaches in Finland right now
| Beach | Region | Sea | Swim score |
|---|---|---|---|
| Yyteri | Finnish Coast | — | — |
| Hietaniemi | Finnish Coast | — | — |
| Hietaniemi Beach | Helsinki | — | — |
| Kaivopuisto Beach | Helsinki | — | — |
| Aurinkolahti Beach | Helsinki | — | — |
| Uunisaari Beach | Helsinki | — | — |
| Ispoinen Beach | Turku Archipelago | — | — |
| Ruissalo Saaronniemi Beach | Turku Archipelago | — | — |
| Lilla Holmen Beach | Aland Islands | — | — |
| Degersand Beach Aland | Aland Islands | — | — |