S
M
T
W
T
F
S
30
89°
70°
31
92°
71°
1
91°
73°
2
90°
72°
3
89°
73°
4
88°
72°
5
88°
72°
6
89°
71°
7
91°
72°
8
91°
71°
9
90°
72°
10
90°
72°
11
89°
73°
12
88°
72°
13
88°
71°
14
89°
72°
15
87°
70°
16
88°
71°
17
91°
72°
18
89°
72°
19
87°
71°
20
89°
72°
21
90°
71°
22
88°
70°
23
88°
71°
24
87°
72°
25
87°
71°
26
89°
71°
27
89°
72°
28
Hist. Avg.
88°
69°
29
Hist. Avg.
88°
68°
30
Hist. Avg.
88°
68°
1
Hist. Avg.
88°
68°
2
Hist. Avg.
88°
68°
3
Hist. Avg.
87°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in San Antonio
San Antonio's September 2026 forecast shows daily high temperatures ranging from 87° to 92°, with overnight lows between 70° and 73°. The average high for September is 89° with an average low of 72°. 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 Antonio. See also: October | November | December.
