Weather in Helsinki in September
September in Helsinki is mild enough that walking is the default. This is a city-break month more than a sea-holiday month.
In Finland, this is how Helsinki actually wears September, not how a country centroid would. Compared with July and February, September sits in the middle of Helsinki's year.
- Average temp
- 12°C
9–15°C
- Rainfall
- 55 mm
Showers likely
- Sunshine
- 5.3 h
hours per day
What to expect
Daytime
Mild afternoons in Helsinki are the prize in September. You can eat outside on the good days. You still want something for the breeze.
This is walking weather. Shade is useful, not essential the way it is in the hot months. A long outdoor day is a reasonable plan.
Rain
Mixed skies in Helsinki in September. Dry days and wet days share the month. Outdoor plans need a backup, not a cancellation policy.
Pack a shell you will actually carry. The monthly table is the place for totals. This is the feel: usable, interrupted.
Evening
Evenings are cooler. A layer helps after sunset.
What to pack
Rain jacket
A layer for cooler evenings
Where to stay in Helsinki
Dates are a starting point for September.
Travel guides for Helsinki
What to read before you book.
Average weather in Helsinki
TemperatureRainfall
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FAQs about Helsinki
Climate averages for Helsinki, 1991–2020.
The best time to visit Helsinki is between May and October, the most comfortable stretch of the year on these averages.
July is the hottest month, with an average around 18°C.
August is the wettest month, with about 84 mm of rain.
No. These are 1991–2020 climate normals from Meteostat, not a live forecast. Actual weather in any given week can differ.
