Current sea water temperature:
+36.7°F
| Minimum sea water temperature in December: | 43.5°F |
| Maximum sea water temperature in December: | 33.3°F |
| Average sea water temperature in December: | 38.7°F |
| more information | |
14 days
forecast
forecast
| Helsinki |
monthly
weather
weather
| Helsinki |
Sea water temperature for the last 10 days:
| December 17 | 36.7°F | December 12 | 40.5°F |
| December 16 | 39.7°F | December 11 | 39.7°F |
| December 15 | 39.9°F | December 10 | 39.4°F |
| December 14 | 40.1°F | December 9 | 39.6°F |
| December 13 | 40.3°F | December 8 | 39.9°F |
Monthly sea water temperature, °F
When is the warmest sea in Helsinki?
Based on the data about daily sea water temperature for the last three years the warmest sea in Helsinki was noticed in August, July and September.
Monthly Sea Temperatures in Helsinki, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
The average sea water temperature in August of 2025 was 63.8°F. The highest and lowest sea temperatures during the month were 73.9°F and 56.5°F.
Sea water temperature in July, °F
Show year:
2025
2024
2023
The average sea water temperature in July of 2025 was 63.2°F. The highest and lowest sea temperatures during the month were 74.5°F and 54.0°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 59.5°F. The highest and lowest sea temperatures during the month were 63.3°F and 54.0°F.
current
weather
weather
| Helsinki |
weather in
December
December
| Helsinki |
Best time for vacation in Helsinki
Helsinki on a weather map
Places in Finland:
Name
°F
24 Hours Forecast
Helsinki
Local time: 01:39
December 18, thursday
0300
39°F
E
14 mph
14 mph
0600
37°F
E
8 mph
8 mph
0900
36°F
E
7 mph
7 mph
1200
37°F
NE
6 mph
6 mph
1500
37°F
NE
8 mph
8 mph
1800
39°F
N
10 mph
10 mph
2100
39°F
NE
13 mph
13 mph
December 19, friday
0000
41°F
NE
16 mph
16 mph
