S
M
T
W
T
F
S
30
80°
49°
31
77°
52°
1
73°
55°
2
74°
56°
3
71°
51°
4
78°
48°
5
82°
49°
6
81°
50°
7
89°
51°
8
92°
55°
9
89°
56°
10
86°
55°
11
82°
54°
12
83°
53°
13
86°
55°
14
88°
55°
15
89°
54°
16
85°
52°
17
86°
53°
18
82°
55°
19
87°
55°
20
87°
54°
21
88°
54°
22
87°
53°
23
81°
54°
24
84°
53°
25
86°
54°
26
88°
55°
27
88°
56°
28
87°
55°
29
87°
54°
30
86°
55°
1
87°
54°
2
84°
54°
3
79°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sonoma
Sonoma's September 2026 forecast shows daily high temperatures ranging from 71° to 92°, with overnight lows between 48° and 56°. The average high for September is 85° with an average low of 54°. 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 Sonoma. See also: October | November | December.
