Swimming in Finland in september 2025 Sea temperature by city in september
Do you want to go to the beach in Finland in september 2025? Is it the right month to go for pleasant temperatures and staying in the water for a long time? The answer is on this page with the sea temperatures in september in Finland by city and our opinion on the chances of enjoying pleasant sea conditions.
Sea temperature in Finland in september 2025
Here, find the average sea temperature in Finland in september in several coastal cities.
South in september
60°F
min: 53°F / max: 67°F
59°F
min: 53°F / max: 66°F
Ekenäs
60°F
min: 54°F / max: 67°F
Hamina
59°F
min: 54°F / max: 65°F
Hanko
59°F
min: 52°F / max: 67°F
Ingå
60°F
min: 53°F / max: 67°F
West Coast in september
50°F
min: 31°F / max: 69°F
51°F
min: 33°F / max: 69°F
55°F
min: 48°F / max: 62°F
Turku Archipelago (Abo Skargard)
50°F
min: 32°F / max: 69°F
Rauma
51°F
min: 34°F / max: 68°F
Jakobstad
54°F
min: 48°F / max: 62°F
Lapland in september
50°F
min: 47°F / max: 53°F
56°F
min: 49°F / max: 61°F
54°F
min: 48°F / max: 59°F
51°F
min: 48°F / max: 54°F
Honningsvåg
49°F
min: 47°F / max: 52°F
49°F
min: 47°F / max: 52°F
North in september
55°F
min: 49°F / max: 61°F
55°F
min: 50°F / max: 62°F
Haukipudas
55°F
min: 50°F / max: 62°F
Kuivaniemi
55°F
min: 49°F / max: 61°F
Pyhaejoki
55°F
min: 49°F / max: 61°F
Raahe
55°F
min: 49°F / max: 61°F
Where should you go swimming in Finland in the month of september?
Swimming in Finland in september is cold (in the best case scenario)
In september in Finland swimming conditions vary by city. Details below:
Swimming in september in Helsinki, Ekenäs, Ingå, Kirkkonummi, Porvoo and Vantaa is possible... with a wetsuit! Indeed, the water is cold at this time of year with an average temperature of 60°F (min: 53°F/max: 67°F).
Forget about swimming in Åland, Alta, Kalajoki, Kemi, Kotka, Lulea, Oulu, Tromso, Turku, Vaasa, Turku Archipelago (Abo Skargard), Honningsvåg, Kirkenes, Rauma, Båtsfjord, Hamina, Hammerfest, Hanko, Haukipudas, Jakobstad, Kokkola, Kristinestad, Kuivaniemi, Lakselv, Lyngseidet, Naantali, Oravais, Pargas, Piteå, Pyhaejoki, Raahe, Skjervoy, Storslett, Tornio, Uusikaupunki, Vadsø and Vardø in september! The water temperature is freezing, reaching as low as 31°F (and only 69°F at the best of times). Our advice: plan on sightseeing, and don't bring your beach towel!
Where to go swimming in Finland in september: the map of sea temperatures
ideal swimming 
pleasant swimming 
cool swimming 
cold swimming 
freezing swimmingWater temperature and seasonal norms in september
Helsinki
| September | |||
| Average sea temperature | 60°F | ||
| Minimum sea temperature | 53°F | ||
| Maximum sea temperature | 67°F | ||
| Average outside temperature | 58°F | ||
| Maximum outside temperature | 61°F | ||
| Minimum outside temperature | 56°F | ||
| Precipitation | 3.1in | ||
| Number of days of precipitation | 5 jour(s) (18%) | ||
| Cloud cover | 46% | ||
| Our opinion | cold swimming |
More information on swimming in Helsinki in september
Åland
| September | |||
| Average sea temperature | 50°F | ||
| Minimum sea temperature | 31°F | ||
| Maximum sea temperature | 69°F | ||
| Average outside temperature | 58°F | ||
| Maximum outside temperature | 59°F | ||
| Minimum outside temperature | 58°F | ||
| Precipitation | 2.7in | ||
| Number of days of precipitation | 4 jour(s) (15%) | ||
| Cloud cover | 42% | ||
| Our opinion | freezing swimming |
More information on swimming in Åland in september
Alta
| September | |||
| Average sea temperature | 50°F | ||
| Minimum sea temperature | 47°F | ||
| Maximum sea temperature | 53°F | ||
| Average outside temperature | 49°F | ||
| Maximum outside temperature | 52°F | ||
| Minimum outside temperature | 45°F | ||
| Precipitation | 2.1in | ||
| Number of days of precipitation | 3 jour(s) (10%) | ||
| Cloud cover | 59% | ||
| Our opinion | freezing swimming |
More information on swimming in Alta in september
Kalajoki
| September | |||
| Average sea temperature | 55°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 61°F | ||
| Average outside temperature | 54°F | ||
| Maximum outside temperature | 58°F | ||
| Minimum outside temperature | 52°F | ||
| Precipitation | 2.5in | ||
| Number of days of precipitation | 4 jour(s) (13%) | ||
| Cloud cover | 50% | ||
| Our opinion | freezing swimming |
More information on swimming in Kalajoki in september
Kemi
| September | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 49°F | ||
| Maximum sea temperature | 61°F | ||
| Average outside temperature | 52°F | ||
| Maximum outside temperature | 56°F | ||
| Minimum outside temperature | 50°F | ||
| Precipitation | 3.9in | ||
| Number of days of precipitation | 6 jour(s) (22%) | ||
| Cloud cover | 52% | ||
| Our opinion | freezing swimming |
More information on swimming in Kemi in september
List of coastal cities in Finland
| Helsinki in september | cold swimming |
| Åland in september | freezing swimming |
| Alta in september | freezing swimming |
| Kalajoki in september | freezing swimming |
| Kemi in september | freezing swimming |
| Kotka in september | freezing swimming |
| Lulea in september | freezing swimming |
| Oulu in september | freezing swimming |
| Tromso in september | freezing swimming |
| Turku in september | freezing swimming |
| Vaasa in september | freezing swimming |
| Turku Archipelago (Abo Skargard) in september | freezing swimming |
| Honningsvåg in september | freezing swimming |
| Kirkenes in september | freezing swimming |
| Rauma in september | freezing swimming |
| Båtsfjord in september | freezing swimming |
| Ekenäs in september | cold swimming |
| Hamina in september | freezing swimming |
| Hammerfest in september | freezing swimming |
| Hanko in september | freezing swimming |
| Haukipudas in september | freezing swimming |
| Ingå in september | cold swimming |
| Jakobstad in september | freezing swimming |
| Kirkkonummi in september | cold swimming |
| Kokkola in september | freezing swimming |
| Kristinestad in september | freezing swimming |
| Kuivaniemi in september | freezing swimming |
| Lakselv in september | freezing swimming |
| Lyngseidet in september | freezing swimming |
| Naantali in september | freezing swimming |
| Oravais in september | freezing swimming |
| Pargas in september | freezing swimming |
| Piteå in september | freezing swimming |
| Porvoo in september | cold swimming |
| Pyhaejoki in september | freezing swimming |
| Raahe in september | freezing swimming |
| Skjervoy in september | freezing swimming |
| Storslett in september | freezing swimming |
| Tornio in september | freezing swimming |
| Uusikaupunki in september | freezing swimming |
| Vadsø in september | freezing swimming |
| Vantaa in september | cold swimming |
| Vardø in september | freezing swimming |