S
M
T
W
T
F
S
30
82°
67°
31
86°
68°
1
89°
72°
2
91°
72°
3
92°
70°
4
88°
69°
5
83°
69°
6
77°
59°
7
78°
56°
8
83°
57°
9
78°
67°
10
80°
57°
11
79°
64°
12
84°
63°
13
79°
51°
14
73°
61°
15
87°
63°
16
79°
64°
17
77°
56°
18
71°
54°
19
68°
51°
20
67°
51°
21
68°
52°
22
73°
55°
23
75°
55°
24
72°
50°
25
71°
55°
26
76°
55°
27
76°
56°
28
75°
55°
29
74°
56°
30
75°
54°
1
73°
51°
2
68°
53°
3
72°
54°
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 67° to 87°, with overnight lows between 50° and 64°. The average high for September is 74° 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 Southwest. See also: October | November | December.
