Verdict: Good month
Helsinki Weather in September
September is mild-to-cool in Helsinki, topping out near 16°C (61°F) — comfortable with a layer on. Expect showers on roughly 10 days of the month — rarely trip-ruining, worth planning around. Overall, September is a solid month to visit Helsinki.
Average high
16°C / 61°F
Average low
10°C / 50°F
Rain days
~10
Precipitation
70 mm
What to pack for Helsinki in September
- Layers — t-shirts under a light jacket or sweater
- A packable rain shell or compact umbrella earns its space
- Comfortable walking shoes — every guide on this site assumes you'll use them
September against the rest of the year
Warmest in Helsinki: Jul (21°C / 70°F) · Coolest: Jan (0°C / 32°F) · Wettest: Jan (~16 rain days)
0°
-5°
Jan
0°
-5°
Feb
2°
-4°
Mar
7°
0°
Apr
13°
6°
May
20°
12°
Jun
21°
14°
Jul
20°
14°
Aug
16°
10°
Sep
10°
6°
Oct
5°
1°
Nov
0°
-4°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)