Average sea water temperature in September:
+58.8°F
| Minimum sea water temperature in September: | 65.8°F |
| Maximum sea water temperature in September: | 50.7°F |
Daily sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 59.3°F. The highest and lowest sea temperatures during the month were 60.8°F and 56.8°F.
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Monthly sea water temperature in Helsinki, °F
Which Finland resorts have warmest sea in September?
| Place name | September 2026 | September 2025 |
|---|---|---|
| Lahti | 61.4°F | 60.6°F |
| Kotka | 61.0°F | 61.4°F |
| Turku | 60.8°F | 60.5°F |
| Lappeenranta | 60.7°F | 61.2°F |
| Juvaskyla | 60.3°F | 59.5°F |
| Savolinna | 59.8°F | 60.1°F |
| Vaasa | 59.6°F | 57.7°F |
| Koli National Park | 59.4°F | 59.1°F |
| Pori | 59.4°F | 57.3°F |
| Imatra | 59.4°F | 59.4°F |
| Vantaa | 59.3°F | 59.5°F |
| Helsinki | 59.3°F | 59.5°F |
| Seinajoki | 58.9°F | 56.7°F |
| Espoo | 58.8°F | 59.3°F |
| Porvoo | 58.7°F | 59.1°F |
| Oulu | 57.2°F | 56.6°F |
| Kemi | 56.6°F | 56.2°F |
| Saariselka | 54.0°F | 53.1°F |
Best time for vacation in Helsinki
Helsinki on a weather map
Places in Finland:
Name
°F
24 Hours Forecast
Helsinki
Local time: 20:30
September 16, wednesday
2100

59°F
N
14 mph
14 mph
September 17, thursday
0000

57°F
NE
9 mph
9 mph
0300

55°F
NE
9 mph
9 mph
0600

55°F
NE
11 mph
11 mph
0900

55°F
NE
10 mph
10 mph
1200

59°F
NE
14 mph
14 mph
1500

59°F
NE
14 mph
14 mph
1800

57°F
E
11 mph
11 mph

























