S
M
T
W
T
F
S
26
65°
51°
27
65°
50°
28
73°
46°
29
76°
49°
30
75°
52°
1
78°
56°
2
78°
54°
3
67°
54°
4
65°
52°
5
64°
53°
6
76°
48°
7
80°
53°
8
78°
56°
9
83°
57°
10
84°
56°
11
90°
57°
12
71°
56°
13
75°
56°
14
74°
53°
15
71°
56°
16
70°
58°
17
66°
57°
18
80°
56°
19
87°
51°
20
88°
58°
21
83°
57°
22
77°
56°
23
78°
56°
24
74°
55°
25
75°
52°
26
69°
54°
27
66°
53°
28
69°
49°
29
69°
54°
30
80°
52°
31
84°
54°
1
83°
57°
2
82°
58°
3
84°
57°
4
84°
58°
5
82°
58°
6
79°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Diamond Bar
Diamond Bar'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 Diamond Bar. See also: June | July | August.
