S
M
T
W
T
F
S
30
85°
49°
31
75°
50°
1
74°
54°
2
75°
58°
3
70°
58°
4
77°
55°
5
80°
48°
6
81°
47°
7
91°
49°
8
98°
51°
9
99°
58°
10
99°
64°
11
81°
57°
12
84°
51°
13
83°
49°
14
85°
50°
15
86°
49°
16
74°
57°
17
78°
52°
18
83°
51°
19
86°
50°
20
75°
54°
21
76°
54°
22
78°
50°
23
87°
49°
24
88°
52°
25
87°
53°
26
84°
49°
27
83°
53°
28
82°
51°
29
84°
53°
30
84°
52°
1
86°
54°
2
81°
49°
3
83°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rohnert Park
Rohnert Park's September 2026 forecast shows daily high temperatures ranging from 75° to 88°, with overnight lows between 49° and 54°. The average high for September is 83° with an average low of 52°. 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 Rohnert Park. See also: October | November | December.
