Average sea water temperature in September:
+59.5°F
| Minimum sea water temperature in September: | 67.5°F |
| Maximum sea water temperature in September: | 51.3°F |
Daily sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 61.4°F. The highest and lowest sea temperatures during the month were 65.1°F and 56.5°F.
Monthly sea water temperature in Kotka, °F
Which Finland resorts have warmest sea in September?
| Place name | September 2026 | September 2025 |
|---|---|---|
| Lahti | 61.7°F | 60.6°F |
| Kotka | 61.2°F | 61.4°F |
| Turku | 60.9°F | 60.5°F |
| Lappeenranta | 60.8°F | 61.2°F |
| Juvaskyla | 60.6°F | 59.5°F |
| Savolinna | 60.1°F | 60.1°F |
| Pori | 59.9°F | 57.3°F |
| Vaasa | 59.9°F | 57.7°F |
| Koli National Park | 59.6°F | 59.1°F |
| Imatra | 59.6°F | 59.4°F |
| Vantaa | 59.6°F | 59.5°F |
| Helsinki | 59.5°F | 59.5°F |
| Seinajoki | 59.3°F | 56.7°F |
| Espoo | 59.0°F | 59.3°F |
| Porvoo | 59.0°F | 59.1°F |
| Oulu | 57.5°F | 56.6°F |
| Kemi | 57.0°F | 56.2°F |
| Saariselka | 54.3°F | 53.1°F |
Best time for vacation in Kotka
Kotka on a weather map
Places in Finland:
Name
°F
24 Hours Forecast
Kotka
Local time: 05:02
September 15, tuesday
0600
50°F
SE
4 mph
4 mph
0900
52°F
SE
4 mph
4 mph
1200
54°F
NE
3 mph
3 mph
1500
55°F
N
7 mph
7 mph
1800
57°F
NE
6 mph
6 mph
2100
57°F
N
7 mph
7 mph
September 16, wednesday
0000
59°F
N
11 mph
11 mph
0300
57°F
NE
10 mph
10 mph
