S
M
T
W
T
F
S
30
73°
57°
31
75°
57°
1
80°
52°
2
79°
47°
3
70°
54°
4
73°
56°
5
70°
48°
6
78°
44°
7
69°
44°
8
69°
46°
9
68°
52°
10
70°
54°
11
72°
53°
12
73°
49°
13
75°
44°
14
67°
42°
15
64°
41°
16
65°
41°
17
65°
46°
18
68°
41°
19
70°
38°
20
63°
44°
21
64°
51°
22
69°
42°
23
72°
49°
24
71°
50°
25
71°
50°
26
69°
49°
27
70°
43°
28
70°
39°
29
59°
44°
30
57°
43°
1
64°
44°
2
65°
47°
3
57°
35°
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 57° to 80°, with overnight lows between 35° and 57°. The average high for September is 69° with an average low of 47°. 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.
