S
M
T
W
T
F
S
30
82°
55°
31
80°
62°
1
67°
60°
2
71°
61°
3
76°
59°
4
81°
58°
5
71°
52°
6
72°
51°
7
76°
53°
8
75°
55°
9
75°
54°
10
78°
57°
11
79°
54°
12
73°
53°
13
74°
54°
14
78°
55°
15
72°
54°
16
73°
55°
17
77°
55°
18
69°
51°
19
70°
51°
20
71°
53°
21
75°
55°
22
76°
55°
23
76°
54°
24
75°
53°
25
74°
52°
26
74°
53°
27
75°
52°
28
74°
51°
29
73°
49°
30
66°
45°
1
63°
45°
2
64°
49°
3
71°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Windham
Windham's September 2026 forecast shows daily high temperatures ranging from 63° to 81°, with overnight lows between 45° and 62°. The average high for September is 73° with an average low of 54°. 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 Windham. See also: October | November | December.