Weather in Helsinki in September
In an average September, Helsinki sees a daily high around 15°C and a low around 8°C, based on 1980–2026 of local climate records.
| Average high | 15°C |
|---|---|
| Typical high range | 11°C to 19°C |
| Average low | 8°C |
| Typical low range | 4°C to 13°C |
| Average daily precipitation | 3 mm |
September records
The most extreme September on record for each metric, across 1980–2026. For rainfall, the wettest and driest are by total September accumulation.
High
Highest
25°C
2024-09-04
Lowest
4°C
1986-09-27
Low
Highest
17°C
2025-09-11
Lowest
-4°C
1986-09-28
Feels-like
Highest
25°C
2024-09-04
Lowest
-13°C
1986-09-28
Humidity
Highest
15.1 g/m³
2025-09-07
Lowest
3.6 g/m³
1986-09-26
Wind
Highest
46 km/h
2023-09-20
Lowest
4 km/h
1992-09-13
Gust
Highest
93 km/h
2023-09-20
Lowest
10 km/h
2010-09-08
Precip
Wettest
145 mm
2012
Driest
15 mm
2002
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