S
M
T
W
T
F
S
26
60°
46°
27
70°
45°
28
60°
49°
29
62°
53°
30
70°
50°
1
67°
45°
2
62°
50°
3
64°
43°
4
78°
50°
5
85°
63°
6
71°
54°
7
60°
46°
8
65°
49°
9
69°
52°
10
77°
61°
11
67°
48°
12
64°
47°
13
69°
52°
14
74°
58°
15
75°
58°
16
77°
57°
17
77°
57°
18
72°
55°
19
76°
58°
20
77°
60°
21
77°
60°
22
74°
52°
23
69°
52°
24
69°
53°
25
70°
55°
26
72°
54°
27
70°
53°
28
71°
55°
29
72°
54°
30
71°
59°
31
74°
62°
1
77°
62°
2
73°
59°
3
74°
60°
4
78°
63°
5
79°
63°
6
81°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Fullerton Heights
Fullerton Heights's May 2026 forecast shows daily high temperatures ranging from 60° to 85°, with overnight lows between 46° and 64°. The average high for May is 73° with an average low of 56°. 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 Heights. See also: June | July | August.
