S
M
T
W
T
F
S
30
90°
64°
31
93°
70°
1
91°
72°
2
90°
70°
3
91°
70°
4
95°
72°
5
95°
72°
6
91°
72°
7
93°
70°
8
93°
70°
9
84°
68°
10
72°
62°
11
77°
63°
12
80°
59°
13
81°
61°
14
82°
62°
15
83°
60°
16
84°
62°
17
82°
62°
18
81°
59°
19
80°
60°
20
81°
60°
21
82°
61°
22
78°
57°
23
77°
58°
24
78°
57°
25
75°
57°
26
71°
54°
27
72°
52°
28
72°
54°
29
74°
52°
30
69°
50°
1
68°
49°
2
68°
49°
3
69°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Possidonio
San Possidonio's September 2026 forecast shows daily high temperatures ranging from 68° to 84°, with overnight lows between 49° and 68°. The average high for September is 77° with an average low of 58°. 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 Possidonio. See also: October | November | December.
