S
M
T
W
T
F
S
30
87°
55°
31
85°
52°
1
82°
48°
2
83°
47°
3
85°
49°
4
84°
51°
5
82°
54°
6
83°
52°
7
82°
51°
8
81°
54°
9
82°
51°
10
84°
51°
11
82°
50°
12
87°
48°
13
86°
50°
14
86°
49°
15
82°
46°
16
79°
48°
17
79°
50°
18
80°
50°
19
81°
51°
20
83°
50°
21
83°
51°
22
84°
52°
23
82°
51°
24
84°
52°
25
85°
52°
26
79°
53°
27
85°
53°
28
86°
52°
29
85°
52°
30
85°
51°
1
86°
52°
2
85°
52°
3
84°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Santa Rosa
Santa Rosa's September 2026 forecast shows daily high temperatures ranging from 79° to 87°, with overnight lows between 46° and 55°. The average high for September is 83° with an average low of 51°. 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 Santa Rosa. See also: October | November | December.
