Current Sea Water Temperature:
+38.6°F
| Maximum Sea Water Temperature in December: | 42.8°F |
| Minimum Sea Water Temperature in December: | 31.4°F |
| Average water temperature in December: | 37.5°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| December 16 | 38.6°F | December 11 | 38.6°F |
| December 15 | 38.8°F | December 10 | 38.2°F |
| December 14 | 39.0°F | December 09 | 38.4°F |
| December 13 | 39.2°F | December 08 | 38.8°F |
| December 12 | 39.4°F | December 07 | 39.2°F |
When is the Warmest Sea for Helsinki?
According to our data for the last three years for Helsinki the highest average sea water temperature was in August, July and September.
Average Water Temperature by Month, °F
Sea Water Temperature in August
The average sea surface temperature in August 2025 for Helsinki was 65.3°F. The maximum and minimum values were 57.2°F and 76.6°F respectively.
Sea Water Temperature in July
The average sea surface temperature in July 2025 for Helsinki was 64.6°F. The maximum and minimum values were 54.4°F and 77.2°F respectively.
Sea Water Temperature in September
The average sea surface temperature in September 2025 for Helsinki was 60.6°F. The maximum and minimum values were 54.4°F and 64.8°F respectively.
Finland Resorts:
NAME
F°
| Espoo |  |
+38 |
| Helsinki | |
+40 |
| Juvaskyla |  |
+36 |
| Kemi | |
+32 |
| Koli National Park | |
+28 |
| Kotka | |
+40 |
| Lahti | |
+36 |
| Lappeenranta | |
+38 |
| Oulu | |
+30 |
| Pori | |
+40 |
| Saariselka | |
+16 |
| Savolinna | |
+32 |
| Turku | |
+40 |
| Vaasa | |
+36 |
| Vantaa | |
+38 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
Helsinki
Local time: 21:11
17 dec, wednesday
| 0000 |  |
40°F | NE 12 mph |
| 0300 | |
40°F | NE 12 mph |
| 0600 | |
40°F | NE 12 mph |
| 0900 | |
40°F | NE 13 mph |
| 1200 | |
40°F | NE 14 mph |
| 1500 | |
40°F | NE 16 mph |
| 1800 | |
40°F | NE 16 mph |
| 2100 | |
42°F | E 19 mph |