S
M
T
W
T
F
S
26
56°
40°
27
56°
40°
28
46°
33°
29
61°
31°
30
55°
36°
1
N/A
2
69°
44°
3
70°
43°
4
76°
42°
5
54°
35°
6
55°
35°
7
67°
42°
8
76°
46°
9
77°
47°
10
72°
44°
11
74°
48°
12
83°
53°
13
81°
49°
14
78°
48°
15
73°
49°
16
73°
55°
17
77°
54°
18
78°
53°
19
78°
48°
20
74°
52°
21
72°
48°
22
69°
46°
23
70°
50°
24
70°
51°
25
69°
49°
26
70°
48°
27
71°
51°
28
69°
54°
29
70°
58°
30
73°
57°
31
72°
50°
1
72°
53°
2
74°
60°
3
80°
60°
4
81°
61°
5
81°
60°
6
76°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Fullerton
Fullerton's May 2026 forecast shows daily high temperatures ranging from 54° to 83°, with overnight lows between 35° and 61°. The average high for May is 73° with an average low of 50°. 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.
