S
M
T
W
T
F
S
30
80°
48°
31
71°
50°
1
72°
55°
2
72°
57°
3
71°
48°
4
76°
48°
5
76°
47°
6
82°
49°
7
88°
49°
8
88°
53°
9
91°
52°
10
92°
52°
11
89°
52°
12
85°
51°
13
86°
52°
14
85°
48°
15
82°
50°
16
79°
50°
17
85°
49°
18
84°
48°
19
78°
47°
20
81°
51°
21
80°
49°
22
83°
48°
23
78°
48°
24
76°
44°
25
76°
45°
26
75°
45°
27
76°
44°
28
76°
44°
29
77°
45°
30
76°
48°
1
75°
44°
2
76°
45°
3
81°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sebastopol
Sebastopol's September 2026 forecast shows daily high temperatures ranging from 71° to 92°, with overnight lows between 44° and 57°. The average high for September is 80° with an average low of 49°. 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 Sebastopol. See also: October | November | December.
