S
M
T
W
T
F
S
30
63°
49°
31
64°
50°
1
66°
49°
2
67°
52°
3
66°
50°
4
65°
47°
5
63°
45°
6
59°
46°
7
59°
46°
8
58°
47°
9
60°
49°
10
60°
47°
11
61°
49°
12
63°
49°
13
64°
47°
14
62°
48°
15
61°
47°
16
60°
46°
17
60°
46°
18
60°
47°
19
58°
46°
20
59°
45°
21
58°
45°
22
58°
47°
23
57°
45°
24
58°
44°
25
57°
45°
26
56°
45°
27
55°
43°
28
56°
43°
29
55°
42°
30
56°
40°
1
54°
39°
2
53°
46°
3
53°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Helsinki
Helsinki's September 2026 forecast shows daily high temperatures ranging from 53° to 67°, with overnight lows between 35° and 52°. The average high for September is 60° with an average low of 46°. 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.
