S
M
T
W
T
F
S
30
86°
63°
31
86°
63°
1
87°
62°
2
82°
56°
3
80°
57°
4
81°
56°
5
82°
56°
6
85°
60°
7
87°
62°
8
87°
62°
9
86°
61°
10
87°
62°
11
86°
61°
12
87°
62°
13
87°
63°
14
85°
58°
15
76°
55°
16
76°
56°
17
78°
54°
18
74°
52°
19
75°
48°
20
74°
50°
21
82°
52°
22
82°
51°
23
81°
48°
24
78°
47°
25
73°
48°
26
77°
53°
27
78°
55°
28
79°
52°
29
72°
45°
30
70°
45°
1
71°
48°
2
78°
47°
3
78°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grantsville
Grantsville's September 2026 forecast shows daily high temperatures ranging from 70° to 87°, with overnight lows between 45° and 63°. The average high for September is 80° with an average low of 55°. 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 Grantsville. See also: October | November | December.
