S
M
T
W
T
F
S
30
85°
65°
31
86°
65°
1
85°
66°
2
85°
64°
3
86°
68°
4
88°
66°
5
88°
68°
6
87°
64°
7
85°
67°
8
86°
67°
9
84°
66°
10
82°
66°
11
86°
65°
12
86°
66°
13
85°
65°
14
86°
65°
15
86°
66°
16
85°
65°
17
85°
65°
18
84°
63°
19
84°
63°
20
83°
58°
21
81°
62°
22
79°
63°
23
84°
62°
24
83°
61°
25
83°
58°
26
81°
61°
27
82°
60°
28
82°
60°
29
81°
59°
30
81°
59°
1
80°
57°
2
82°
59°
3
76°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Southwest
Southwest's September 2026 forecast shows daily high temperatures ranging from 76° to 88°, with overnight lows between 57° and 68°. The average high for September is 84° with an average low of 63°. 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 Southwest. See also: October | November | December.
