S
M
T
W
T
F
S
30
80°
55°
31
82°
54°
1
81°
53°
2
82°
53°
3
84°
52°
4
79°
54°
5
79°
54°
6
80°
51°
7
85°
55°
8
85°
55°
9
84°
54°
10
86°
55°
11
85°
55°
12
82°
54°
13
80°
53°
14
79°
53°
15
80°
53°
16
83°
54°
17
85°
56°
18
87°
54°
19
86°
53°
20
86°
54°
21
85°
54°
22
85°
53°
23
83°
53°
24
81°
52°
25
84°
53°
26
85°
54°
27
85°
53°
28
84°
53°
29
82°
50°
30
84°
53°
1
81°
48°
2
76°
45°
3
77°
46°
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 76° to 87°, with overnight lows between 45° and 56°. The average high for September is 83° 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 Rohnert Park. See also: October | November | December.
