S
M
T
W
T
F
S
26
69°
55°
27
70°
55°
28
74°
51°
29
74°
53°
30
74°
59°
1
75°
60°
2
73°
59°
3
70°
58°
4
70°
56°
5
70°
56°
6
75°
55°
7
76°
57°
8
76°
61°
9
77°
61°
10
77°
61°
11
85°
58°
12
70°
59°
13
74°
60°
14
73°
59°
15
73°
61°
16
73°
61°
17
72°
59°
18
75°
61°
19
89°
56°
20
89°
57°
21
79°
61°
22
73°
61°
23
76°
62°
24
74°
60°
25
73°
57°
26
71°
60°
27
70°
58°
28
72°
55°
29
74°
59°
30
79°
56°
31
79°
60°
1
77°
62°
2
77°
62°
3
79°
63°
4
76°
63°
5
75°
64°
6
75°
64°
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 ° to °, with overnight lows between ° and °. The average high for May 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 May weather will actually feel in Fullerton. See also: June | July | August.
