Weather in Helsinki: September
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Average day temperature: | 59.3°F |
| Average night temperature: | 52.8°F | |
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Sea water temperature: | 58.8°F |
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Number of sunny days: | 9 days |
| Day length: | 11.5 - 14.2 hours | |
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Number of rainy days: | 3 days |
| Precipitation totals: | 1.7 in. | |
| more information | ||
forecast
| Helsinki |
temperature
| Helsinki |
Air temperature in September, °F
The highest day temperature during September of 2026 was 66°F. At the same time the lowest night temperature was 42°F. Daily and nightly averages during September were 59.1°F and 52.3°F.
Sea water temperature in Helsinki in September, °F
The average sea water temperature in September of 2026 was 58.0°F. The highest and lowest sea temperatures during the month were 60.8°F and 54.5°F.
Number of sunny, partly cloudy and cloudy days in September is almost equal.
Precipitation total in September, in.
Precipitation total value in Helsinki in September is 1.5 in. Other months of the year show relatively similar values.
The average wind speed value in September is 9.6 mph
This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 6.7.
Best time for vacation in Helsinki
Helsinki on a weather map
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