S
M
T
W
T
F
S
30
106°
77°
31
86°
73°
1
101°
77°
2
102°
79°
3
100°
79°
4
101°
76°
5
100°
78°
6
99°
81°
7
102°
80°
8
100°
81°
9
97°
79°
10
102°
80°
11
98°
79°
12
98°
74°
13
95°
80°
14
99°
72°
15
101°
75°
16
102°
76°
17
102°
76°
18
101°
75°
19
101°
75°
20
100°
74°
21
100°
71°
22
99°
73°
23
100°
73°
24
99°
72°
25
97°
73°
26
94°
70°
27
92°
66°
28
91°
67°
29
94°
69°
30
94°
67°
1
93°
69°
2
94°
70°
3
94°
70°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Tan Valley
San Tan Valley's September 2026 forecast shows daily high temperatures ranging from 91° to 102°, with overnight lows between 66° and 81°. The average high for September is 98° with an average low of 74°. 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 San Tan Valley. See also: October | November | December.
