S
M
T
W
T
F
S
26
32°
21°
27
37°
21°
28
52°
23°
29
52°
28°
30
57°
32°
1
68°
34°
2
61°
37°
3
70°
37°
4
50°
25°
5
45°
23°
6
61°
19°
7
63°
41°
8
N/A
9
62°
42°
10
79°
51°
11
83°
42°
12
78°
47°
13
87°
51°
14
80°
49°
15
77°
44°
16
73°
43°
17
71°
42°
18
76°
43°
19
81°
46°
20
80°
46°
21
74°
47°
22
71°
42°
23
73°
47°
24
75°
46°
25
69°
47°
26
66°
48°
27
66°
45°
28
64°
41°
29
66°
42°
30
69°
46°
31
72°
49°
1
66°
49°
2
69°
47°
3
68°
46°
4
72°
50°
5
78°
51°
6
79°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Roundup
Roundup's May 2026 forecast shows daily high temperatures ranging from 62° to 87°, with overnight lows between 41° and 51°. The average high for May is 73° with an average low of 46°. 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 Roundup. See also: June | July | August.
