S
M
T
W
T
F
S
30
81°
55°
31
77°
57°
1
73°
54°
2
77°
48°
3
77°
57°
4
86°
63°
5
73°
54°
6
75°
46°
7
81°
46°
8
90°
52°
9
70°
54°
10
64°
48°
11
68°
45°
12
73°
45°
13
73°
52°
14
72°
54°
15
75°
54°
16
81°
54°
17
68°
46°
18
68°
46°
19
72°
46°
20
75°
48°
21
63°
43°
22
63°
37°
23
66°
37°
24
63°
41°
25
66°
36°
26
75°
37°
27
73°
41°
28
79°
41°
29
N/A
30
74°
50°
1
75°
55°
2
63°
51°
3
68°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Altdorf
Altdorf's September 2026 forecast shows daily high temperatures ranging from 63° to 75°, with overnight lows between 50° and 55°. The average high for September is 70° 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 Altdorf. See also: October | November | December.
