In May warmest sea in Finland is usually observed in the following locations: Lahti, Porvoo, Lappeenranta.
Table below shows the average sea water temperature for marine resorts of Finland in May for the last three years.
| Place name | May 2026 | May 2025 | May 2024 |
|---|---|---|---|
| Lahti | 49.7°F | 47.5°F | 49.8°F |
| Porvoo | 48.9°F | 47.1°F | 48.2°F |
| Lappeenranta | 48.4°F | 46.3°F | 50.3°F |
| Vaasa | 48.0°F | 47.1°F | 45.3°F |
| Pori | 47.2°F | 46.9°F | 44.8°F |
| Seinajoki | 46.5°F | 45.2°F | 43.4°F |
| Helsinki | 46.3°F | 46.3°F | 46.4°F |
| Espoo | 46.2°F | 46.2°F | 46.8°F |
| Turku | 46.0°F | 45.7°F | 48.4°F |
| Juvaskyla | 46.0°F | 43.8°F | 45.6°F |
| Vantaa | 45.9°F | 46.0°F | 46.4°F |
| Kotka | 45.5°F | 45.7°F | 48.1°F |
| Savolinna | 45.5°F | 43.1°F | 42.4°F |
| Imatra | 44.7°F | 43.1°F | 45.3°F |
| Oulu | 41.1°F | 39.1°F | 40.6°F |
| Kemi | 38.5°F | 37.6°F | 35.1°F |
| Koli National Park | 38.5°F | 39.1°F | 40.8°F |
| Saariselka | 38.0°F | 38.1°F | 38.1°F |
Charts below show average sea water temperature for Finland resorts with the warmest sea in May.
You can also check other months of the year to see sea temperature of Finland resorts at that time.
Places in Finland:
Name
°F
