S
M
T
W
T
F
S
30
64°
46°
31
62°
44°
1
56°
42°
2
60°
37°
3
63°
36°
4
67°
35°
5
69°
39°
6
70°
40°
7
66°
38°
8
64°
36°
9
65°
40°
10
62°
37°
11
57°
37°
12
56°
35°
13
56°
36°
14
55°
38°
15
56°
36°
16
54°
39°
17
54°
39°
18
55°
34°
19
55°
33°
20
58°
34°
21
60°
41°
22
59°
41°
23
60°
37°
24
61°
39°
25
60°
36°
26
51°
34°
27
50°
34°
28
50°
37°
29
51°
32°
30
50°
31°
1
50°
38°
2
51°
37°
3
49°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Houston
Houston's September 2026 forecast shows daily high temperatures ranging from 49° to 70°, with overnight lows between 31° and 46°. The average high for September is 58° with an average low of 37°. 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 Houston. See also: October | November | December.