Finland: where to swim in October?
Finland, in October: the sea is at 9.8 °C on average along the coast, from 8.4 °C to 11.3 °C depending on the spot. Where the water is warmest (11.3 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.
Sea temperature, month by month
| Month | Average temperature | Depending on the spot | Where it is warmest |
|---|---|---|---|
| January | 1.9 °C | 0.3 °C – 3.1 °C | very cold |
| February | 0.9 °C | 0.0 °C – 1.8 °C | very cold |
| March | 0.8 °C | 0.2 °C – 1.6 °C | very cold |
| April | 1.8 °C | 0.3 °C – 3.1 °C | very cold |
| May | 4.9 °C | 2.1 °C – 7.1 °C | very cold |
| June | 11.2 °C | 9.6 °C – 12.9 °C | cold |
| July | 16.1 °C | 15.3 °C – 17.0 °C | cool |
| August | 16.8 °C | 15.9 °C – 17.7 °C | cool |
| September | 14.1 °C | 13.0 °C – 15.2 °C | cool |
| October | 9.8 °C | 8.4 °C – 11.3 °C | cold |
| November | 6.6 °C | 4.8 °C – 8.6 °C | very cold |
| December | 3.8 °C | 2.0 °C – 5.2 °C | very cold |
Compared with September, the water cools down by 4.3 °C in October. The warmest month: August (16.8 °C). The coldest: March (0.8 °C).
Nearby, in October
- Sweden 10.5 °C · cold
- Latvia 12.3 °C · cold
- Lithuania 13.4 °C · cold
- Denmark 13.0 °C · cold
- Poland 13.1 °C · cold
- Germany 13.7 °C · cold
- Netherlands 15.2 °C · cool
- United Kingdom 12.9 °C · cool
And right now?
At sea, 8.9 °C on average across 19 stations, from 6.1 °C (Kemi Ajos) to 12.0 °C (Suomenlahti (bouée)). In fresh water, 6.8 °C on average across 29 stations, from 3.0 °C (Inari, Nellim (Inarijärvi l. Anarjävri)) to 10.7 °C (Saimaa, Lauritsala). Finland: water temperature
Frequently asked questions
What is the sea temperature in October?
Finland, in October: 9.8 °C on average along the coast, from 8.4 °C in the coolest waters to 11.3 °C in the warmest (average of the years 2011 to 2025).
Can you swim in October?
Where the water is warmest (11.3 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.
What is the best month for swimming?
The water is warmest in August (16.8 °C on average) and coldest in March (0.8 °C). Even where it is warmest, the water never reaches 20 °C in any month; the three warmest months are: August, July, September.
Where is the water warmest in October?
The warmest in October: Sweden (10.5 °C), Latvia (12.3 °C), Lithuania (13.4 °C). The coolest: United Kingdom (12.9 °C).
Where do these temperatures come from?
These are averages of the sea surface temperature from 2011 to 2025, computed from NOAA satellite images (OISST, one value about every 50 km), in a 100 km strip along the coasts of the main country: distant territories (overseas, remote islands) are not counted. It is an estimate, not a measurement taken at the beach: lakes and rivers are not included.