Helsinki in September

In September, Helsinki averages 15°C (59°F) during the day and 8°C (46°F) at night, with around 13 days of rain (70 mm total).

Conditions are cool — bring a jacket for evenings. Plan for unsettled weather and bring rain gear.

September in Helsinki is outside the typical sweet spot for sightseeing weather. It can still be a great time to visit if you have specific reasons (festivals, off-season pricing, etc.).

15°C

Avg high

8°C

Avg low

Rain days

70 mm

Rainfall

Helsinki in other months

January February March April May June July August September October November December

Month	Avg high	Avg low	Rainfall	Rain days	Snow days
January	-3°C / 27°F	-7°C / 19°F	55 mm	17	11
February	-3°C / 27°F	-8°C / 18°F	40 mm	15	11
March	1°C / 34°F	-5°C / 23°F	40 mm	12	7
April	8°C / 46°F	0°C / 32°F	35 mm	11	2
May	15°C / 59°F	5°C / 41°F	40 mm	11	0
June	19°C / 66°F	11°C / 52°F	55 mm	12	0
July	22°C / 72°F	14°C / 57°F	75 mm	12	0
August	20°C / 68°F	13°C / 55°F	80 mm	13	0
September	15°C / 59°F	8°C / 46°F	70 mm	13	0
October	8°C / 46°F	3°C / 37°F	80 mm	15	0
November	3°C / 37°F	-1°C / 30°F	70 mm	16	5
December	-1°C / 30°F	-5°C / 23°F	55 mm	17	9