Weather in Helsinki, Uusimaa, Finland in September
In an average September, Helsinki sees a daily high around 14°C and a low around 11°C, based on 1981–2026 of local climate records.
| Average high | 14°C |
|---|---|
| Typical high range | 11°C to 18°C |
| Average low | 11°C |
| Typical low range | 8°C to 14°C |
| Average daily precipitation | 3 mm |
September records
The most extreme September on record for each metric, across 1981–2026. For rainfall, the wettest and driest are by total September accumulation.
High
Highest
23°C
2024-09-05
Lowest
6°C
1986-09-27
Low
Highest
18°C
2024-09-05
Lowest
2°C
1986-09-28
Feels-like
Highest
23°C
2024-09-05
Lowest
-6°C
1986-09-28
Humidity
Highest
14.9 g/m³
2025-09-07
Lowest
4.6 g/m³
1986-09-26
Wind
Highest
53 km/h
2023-09-20
Lowest
6 km/h
2005-09-02
Precip
Wettest
148 mm
1987
Driest
19 mm
2000
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