S
M
T
W
T
F
S
30
53°
42°
31
52°
40°
1
51°
39°
2
51°
38°
3
52°
37°
4
50°
38°
5
49°
37°
6
49°
37°
7
50°
35°
8
48°
35°
9
47°
34°
10
47°
31°
11
48°
31°
12
46°
33°
13
46°
33°
14
51°
32°
15
51°
33°
16
51°
33°
17
50°
34°
18
54°
36°
19
58°
33°
20
56°
30°
21
45°
27°
22
43°
29°
23
45°
24°
24
44°
26°
25
42°
32°
26
45°
29°
27
47°
31°
28
43°
30°
29
43°
29°
30
44°
27°
1
44°
26°
2
43°
31°
3
46°
33°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Summit
Summit's September 2026 forecast shows daily high temperatures ranging from 42° to 58°, with overnight lows between 24° and 42°. The average high for September is 48° with an average low of 33°. 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 Summit. See also: October | November | December.
