Helsinki weather in September
Helsinki in September averages 12°C (54°F), 55 mm of rain and 5.3 hours of sun a day.
Of the twelve months in Helsinki, September is the fourth warmest, the sixth driest and the sixth sunniest.
- Average temp
- 12°C (54°F)
9–15°C · 49–60°F
- Rainfall
- 55 mm
Showers likely
- Sunshine
- 5.3 h
hours per day
What is Helsinki like in September?
Daytime
Days are cool.
Rain
Some rain is likely; pack for showers.
Evening
Evenings are cooler. A layer helps after sunset.
What should I pack for Helsinki in September?
A light rain jacket
About 55 mm falls this month — showers rather than washouts.
A warm mid-layer
Nights drop to around 9°C (49°F).
September compared with August and October
September in Helsinki is 4.8°C cooler than August and 29 mm drier than it, which averages 17°C (63°F).
September in Helsinki is 5.4°C warmer than October and 20 mm drier than it, which averages 7°C (44°F).
Daylight in Helsinki in September
On 15 September the sun is up for 12 hours 52 minutes in Helsinki, rising about 06:48 and setting about 19:40 local time.
September ends 2 hours 38 minutes shorter than it begins, so the last week of the month is a different length of day from the first.
That is 6 hours 1 minute short of June, the longest-lit month here.
Where to stay in Helsinki
Dates are a starting point for September.
Travel guides for Helsinki
What to read before you book.
Helsinki weather by month
TemperatureRainfall
How September compares with the rest of the year
September is highlighted. Every other month links to its own page.
| Month | Average | Rainfall |
|---|---|---|
| January | -3°C / 26°F | 54 mm |
| February | -4°C / 25°F | 38 mm |
| March | -1°C / 31°F | 35 mm |
| April | 5°C / 40°F | 32 mm |
| May | 10°C / 51°F | 41 mm |
| June | 15°C / 59°F | 56 mm |
| July | 18°C / 65°F | 58 mm |
| August | 17°C / 63°F | 84 mm |
| September | 12°C / 54°F | 55 mm |
| October | 7°C / 44°F | 75 mm |
| November | 2°C / 36°F | 70 mm |
| December | -1°C / 30°F | 59 mm |
Check another month
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FAQs about Helsinki in September
September climate averages for Helsinki, 1991–2020.
Helsinki averages 12°C (54°F) in September, ranging from about 9°C (49°F) at night to 15°C (60°F) in the afternoon. That is a 1991–2020 average, so an individual week can run either side of it.
Some. About 55 mm falls across September, enough to need a light jacket but not enough to reshape a trip.
Yes. September averages 12°C (54°F) against 7°C (44°F) in October — 5.4°C warmer.
September is 4.8°C cooler than August, and 29 mm drier.
Yes. September falls inside the most comfortable stretch of the year here, May to October, on temperature and rainfall together.
About 5.3 hours of sun a day on the 1991–2020 average.
This page does not show today's weather. It is a 1991–2020 climate normal from Meteostat — a long-run average of what September is usually like, which is what you want when booking months ahead. For today or the coming week, check a live forecast.
About 12 hours 52 minutes of daylight in mid-September, against 18 hours 53 minutes in June and 5 hours 52 minutes in December.
On 15 September, sunrise is about 06:48 and sunset about 19:40 local time. Both shift across the month — the month ends 2 hours 38 minutes shorter than it starts.
