S
M
T
W
T
F
S
30
65°
56°
31
65°
57°
1
69°
61°
2
70°
61°
3
71°
60°
4
68°
57°
5
71°
56°
6
69°
57°
7
81°
57°
8
85°
61°
9
94°
65°
10
76°
59°
11
66°
58°
12
68°
59°
13
66°
58°
14
71°
57°
15
66°
57°
16
63°
57°
17
70°
59°
18
66°
57°
19
66°
57°
20
60°
55°
21
61°
56°
22
62°
56°
23
75°
56°
24
75°
58°
25
67°
57°
26
68°
56°
27
63°
55°
28
70°
54°
29
76°
56°
30
74°
56°
1
73°
57°
2
77°
56°
3
77°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Francisco
San Francisco's September 2026 forecast shows daily high temperatures ranging from 63° to 77°, with overnight lows between 54° and 58°. The average high for September is 73° with an average low of 56°. 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.
