S
M
T
W
T
F
S
30
82°
48°
31
70°
49°
1
73°
58°
2
73°
56°
3
68°
59°
4
75°
54°
5
79°
48°
6
75°
47°
7
90°
48°
8
96°
50°
9
99°
57°
10
91°
64°
11
75°
56°
12
76°
51°
13
74°
49°
14
85°
50°
15
84°
47°
16
71°
57°
17
76°
56°
18
78°
54°
19
81°
52°
20
74°
55°
21
76°
55°
22
78°
53°
23
87°
50°
24
89°
50°
25
78°
56°
26
77°
46°
27
75°
52°
28
77°
48°
29
91°
47°
30
91°
51°
1
89°
46°
2
91°
49°
3
100°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Petaluma
Petaluma's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Petaluma. See also: October | November | December.
