S
M
T
W
T
F
S
30
81°
53°
31
81°
56°
1
84°
57°
2
86°
57°
3
86°
55°
4
80°
56°
5
80°
54°
6
82°
51°
7
80°
52°
8
81°
53°
9
83°
55°
10
85°
56°
11
86°
56°
12
86°
55°
13
87°
55°
14
86°
52°
15
81°
52°
16
83°
55°
17
85°
56°
18
85°
56°
19
86°
53°
20
86°
55°
21
85°
56°
22
82°
52°
23
79°
50°
24
78°
49°
25
77°
48°
26
78°
50°
27
77°
52°
28
79°
51°
29
84°
48°
30
80°
54°
1
Hist. Avg.
79°
53°
2
Hist. Avg.
78°
53°
3
Hist. Avg.
78°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Rafael
San Rafael's September 2026 forecast shows daily high temperatures ranging from 77° to 87°, with overnight lows between 48° and 57°. The average high for September is 82° with an average low of 53°. 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 Rafael. See also: October | November | December.
