S
M
T
W
T
F
S
26
60°
50°
27
64°
45°
28
70°
42°
29
71°
49°
30
74°
45°
1
72°
50°
2
60°
52°
3
63°
52°
4
64°
44°
5
63°
52°
6
68°
54°
7
64°
51°
8
66°
50°
9
73°
45°
10
76°
51°
11
74°
49°
12
64°
50°
13
75°
45°
14
79°
47°
15
83°
50°
16
76°
48°
17
80°
49°
18
87°
52°
19
85°
51°
20
77°
52°
21
73°
53°
22
74°
50°
23
73°
51°
24
74°
48°
25
73°
48°
26
74°
49°
27
68°
49°
28
69°
47°
29
69°
46°
30
70°
46°
31
73°
49°
1
73°
50°
2
77°
52°
3
77°
50°
4
70°
48°
5
72°
51°
6
76°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Petaluma
Petaluma's May 2026 forecast shows daily high temperatures ranging from 68° to 87°, with overnight lows between 45° and 53°. The average high for May is 75° 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 May weather will actually feel in Petaluma. See also: June | July | August.
