S
M
T
W
T
F
S
30
76°
60°
31
82°
56°
1
81°
58°
2
84°
55°
3
84°
54°
4
88°
54°
5
87°
59°
6
86°
58°
7
84°
61°
8
82°
57°
9
77°
50°
10
83°
50°
11
85°
50°
12
69°
45°
13
87°
52°
14
85°
54°
15
67°
47°
16
76°
48°
17
74°
57°
18
81°
53°
19
73°
51°
20
64°
45°
21
69°
41°
22
77°
50°
23
73°
52°
24
70°
50°
25
70°
51°
26
80°
50°
27
78°
53°
28
70°
45°
29
59°
42°
30
69°
42°
1
72°
46°
2
70°
43°
3
70°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Cheyenne
Cheyenne's September 2026 forecast shows daily high temperatures ranging from 59° to 80°, with overnight lows between 42° and 53°. The average high for September is 71° with an average low of 47°. 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 Cheyenne. See also: October | November | December.