S
M
T
W
T
F
S
26
41°
27°
27
39°
25°
28
43°
24°
29
45°
17°
30
50°
25°
1
57°
18°
2
63°
23°
3
64°
27°
4
64°
27°
5
46°
28°
6
54°
21°
7
61°
32°
8
64°
30°
9
59°
30°
10
68°
27°
11
77°
28°
12
77°
30°
13
79°
32°
14
63°
28°
15
64°
27°
16
61°
23°
17
50°
30°
18
39°
30°
19
50°
23°
20
54°
21°
21
45°
28°
22
54°
30°
23
68°
28°
24
72°
32°
25
70°
32°
26
N/A
27
74°
42°
28
77°
42°
29
76°
39°
30
58°
34°
31
69°
35°
1
67°
33°
2
72°
31°
3
71°
34°
4
78°
39°
5
76°
41°
6
74°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Boulder
Boulder's May 2026 forecast shows daily high temperatures ranging from 58° to 78°, with overnight lows between 31° and 42°. The average high for May is 72° with an average low of 37°. 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 Boulder. See also: June | July | August.
