S
M
T
W
T
F
S
30
86°
67°
31
87°
65°
1
88°
67°
2
90°
68°
3
90°
67°
4
89°
67°
5
85°
66°
6
84°
62°
7
87°
62°
8
87°
63°
9
88°
64°
10
89°
65°
11
90°
65°
12
89°
64°
13
89°
63°
14
87°
64°
15
88°
64°
16
82°
62°
17
87°
64°
18
86°
63°
19
Hist. Avg.
85°
64°
20
Hist. Avg.
85°
64°
21
Hist. Avg.
85°
64°
22
Hist. Avg.
84°
64°
23
Hist. Avg.
84°
63°
24
Hist. Avg.
84°
63°
25
Hist. Avg.
84°
62°
26
Hist. Avg.
83°
62°
27
Hist. Avg.
83°
62°
28
Hist. Avg.
82°
61°
29
Hist. Avg.
82°
61°
30
Hist. Avg.
82°
61°
1
Hist. Avg.
82°
60°
2
Hist. Avg.
81°
60°
3
Hist. Avg.
81°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Grayson Valley
Grayson Valley's September 2026 forecast shows daily high temperatures ranging from 82° to 90°, with overnight lows between 62° and 68°. The average high for September is 87° with an average low of 65°. 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 Grayson Valley. See also: October | November | December.
