S
M
T
W
T
F
S
31
90°
64°
1
90°
62°
2
90°
57°
3
94°
64°
4
88°
59°
5
86°
64°
6
84°
60°
7
89°
57°
8
90°
54°
9
92°
55°
10
94°
64°
11
94°
63°
12
90°
64°
13
74°
58°
14
82°
53°
15
88°
50°
16
90°
57°
17
88°
55°
18
88°
58°
19
82°
57°
20
85°
54°
21
90°
53°
22
84°
57°
23
82°
54°
24
79°
46°
25
83°
48°
26
82°
57°
27
77°
57°
28
76°
55°
29
76°
54°
30
82°
55°
1
82°
55°
2
85°
50°
3
86°
53°
4
86°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Francisco
San Francisco'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 Francisco. See also: October | November | December.
