S
M
T
W
T
F
S
31
100°
74°
1
89°
75°
2
99°
74°
3
100°
75°
4
103°
70°
5
101°
75°
6
94°
77°
7
79°
73°
8
89°
71°
9
94°
67°
10
96°
69°
11
97°
68°
12
98°
76°
13
96°
72°
14
97°
72°
15
96°
70°
16
96°
72°
17
95°
71°
18
96°
71°
19
97°
71°
20
96°
70°
21
98°
76°
22
100°
77°
23
101°
79°
24
97°
79°
25
95°
77°
26
93°
71°
27
94°
66°
28
92°
68°
29
90°
67°
30
95°
68°
1
96°
66°
2
95°
67°
3
96°
69°
4
92°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Antonio
San Antonio's September 2025 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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.
