S
M
T
W
T
F
S
30
90°
62°
31
74°
60°
1
86°
54°
2
86°
59°
3
84°
59°
4
85°
63°
5
89°
57°
6
89°
62°
7
90°
66°
8
92°
67°
9
92°
67°
10
90°
65°
11
88°
62°
12
87°
64°
13
85°
63°
14
84°
62°
15
82°
61°
16
84°
64°
17
84°
63°
18
86°
62°
19
85°
61°
20
84°
52°
21
78°
52°
22
79°
50°
23
82°
53°
24
80°
51°
25
82°
52°
26
85°
54°
27
80°
52°
28
76°
46°
29
77°
46°
30
75°
42°
1
74°
42°
2
75°
45°
3
78°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Star Valley
Star Valley's September 2026 forecast shows daily high temperatures ranging from 74° to 92°, with overnight lows between 42° and 67°. The average high for September is 83° with an average low of 56°. 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 Star Valley. See also: October | November | December.
