S
M
T
W
T
F
S
26
61°
41°
27
71°
35°
28
60°
39°
29
62°
48°
30
61°
46°
1
62°
46°
2
58°
37°
3
57°
39°
4
67°
49°
5
76°
54°
6
68°
52°
7
63°
40°
8
59°
41°
9
61°
47°
10
67°
48°
11
64°
49°
12
65°
50°
13
64°
49°
14
67°
50°
15
67°
51°
16
68°
52°
17
68°
50°
18
69°
56°
19
76°
56°
20
75°
55°
21
73°
57°
22
77°
54°
23
70°
53°
24
74°
53°
25
70°
50°
26
70°
54°
27
69°
57°
28
72°
59°
29
78°
59°
30
77°
58°
31
77°
55°
1
73°
52°
2
69°
52°
3
70°
53°
4
72°
52°
5
72°
53°
6
73°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Fullerton
Fullerton's May 2026 forecast shows daily high temperatures ranging from 57° to 78°, with overnight lows between 37° and 59°. The average high for May is 69° with an average low of 51°. 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 Fullerton. See also: June | July | August.
