S
M
T
W
T
F
S
30
81°
64°
31
77°
57°
1
75°
57°
2
73°
55°
3
77°
55°
4
81°
61°
5
70°
57°
6
68°
50°
7
68°
50°
8
83°
63°
9
68°
53°
10
66°
47°
11
69°
50°
12
68°
51°
13
72°
54°
14
70°
51°
15
74°
56°
16
70°
51°
17
68°
52°
18
69°
51°
19
69°
52°
20
68°
51°
21
62°
52°
22
65°
52°
23
67°
51°
24
68°
52°
25
68°
50°
26
67°
46°
27
61°
43°
28
60°
43°
29
58°
44°
30
59°
49°
1
57°
47°
2
61°
43°
3
62°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grünau
Grünau's September 2026 forecast shows daily high temperatures ranging from 57° to 83°, with overnight lows between 43° and 63°. The average high for September is 67° with an average low of 50°. 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 Grünau. See also: October | November | December.