S
M
T
W
T
F
S
30
70°
59°
31
N/A
1
67°
55°
2
66°
58°
3
68°
58°
4
67°
57°
5
66°
54°
6
67°
54°
7
68°
55°
8
67°
54°
9
66°
54°
10
67°
52°
11
67°
54°
12
65°
53°
13
64°
52°
14
64°
51°
15
63°
50°
16
63°
53°
17
64°
53°
18
65°
52°
19
65°
51°
20
63°
51°
21
61°
52°
22
61°
52°
23
64°
51°
24
63°
49°
25
62°
51°
26
63°
50°
27
62°
51°
28
62°
51°
29
61°
48°
30
62°
51°
1
62°
51°
2
61°
50°
3
61°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Flensburg
Flensburg's September 2026 forecast shows daily high temperatures ranging from 61° to 68°, with overnight lows between 48° and 58°. The average high for September is 64° with an average low of 52°. 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 Flensburg. See also: October | November | December.
