S
M
T
W
T
F
S
26
44°
21°
27
43°
22°
28
49°
25°
29
43°
19°
30
44°
21°
1
45°
20°
2
44°
18°
3
43°
18°
4
45°
19°
5
47°
21°
6
48°
23°
7
48°
23°
8
49°
24°
9
50°
23°
10
53°
25°
11
52°
25°
12
51°
26°
13
52°
26°
14
53°
27°
15
51°
27°
16
52°
28°
17
53°
27°
18
54°
27°
19
57°
28°
20
58°
29°
21
61°
29°
22
62°
30°
23
56°
29°
24
55°
29°
25
56°
30°
26
57°
33°
27
58°
35°
28
57°
35°
29
60°
35°
30
60°
36°
31
62°
36°
1
61°
34°
2
60°
38°
3
64°
35°
4
61°
35°
5
61°
36°
6
62°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Richardson
Richardson's May 2026 forecast shows daily high temperatures ranging from 43° to 64°, with overnight lows between 18° and 40°. The average high for May is 53° with an average low of 28°. 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 Richardson. See also: June | July | August.