S
M
T
W
T
F
S
30
72°
51°
31
72°
50°
1
73°
49°
2
73°
54°
3
79°
51°
4
78°
56°
5
73°
53°
6
77°
49°
7
76°
47°
8
74°
50°
9
72°
46°
10
75°
53°
11
76°
49°
12
76°
46°
13
70°
49°
14
72°
56°
15
76°
49°
16
79°
43°
17
76°
42°
18
66°
40°
19
65°
41°
20
65°
44°
21
66°
42°
22
72°
46°
23
67°
41°
24
65°
40°
25
65°
39°
26
64°
41°
27
65°
41°
28
64°
40°
29
62°
40°
30
64°
38°
1
Hist. Avg.
65°
43°
2
Hist. Avg.
65°
43°
3
Hist. Avg.
64°
42°
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 62° to 79°, with overnight lows between 38° and 56°. The average high for September is 71° with an average low of 46°. 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.
