S
M
T
W
T
F
S
31
68°
59°
1
61°
49°
2
64°
46°
3
64°
60°
4
63°
59°
5
61°
58°
6
64°
58°
7
65°
61°
8
65°
59°
9
67°
62°
10
66°
64°
11
66°
63°
12
62°
59°
13
64°
60°
14
63°
60°
15
63°
57°
16
63°
57°
17
62°
56°
18
62°
56°
19
62°
56°
20
63°
57°
21
65°
60°
22
61°
51°
23
53°
46°
24
53°
44°
25
57°
44°
26
56°
49°
27
60°
49°
28
55°
49°
29
51°
48°
30
52°
49°
1
54°
50°
2
52°
47°
3
51°
46°
4
52°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Helsinki
Helsinki's September 2025 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Helsinki. See also: October | November | December.
