S
M
T
W
T
F
S
26
39°
28°
27
50°
29°
28
57°
38°
29
59°
33°
30
64°
32°
1
72°
32°
2
69°
39°
3
76°
43°
4
59°
39°
5
50°
32°
6
74°
27°
7
65°
47°
8
74°
41°
9
70°
48°
10
79°
42°
11
77°
46°
12
80°
42°
13
84°
48°
14
64°
48°
15
63°
45°
16
52°
39°
17
45°
33°
18
55°
33°
19
63°
29°
20
61°
34°
21
59°
41°
22
66°
37°
23
73°
43°
24
81°
44°
25
83°
50°
26
74°
47°
27
64°
46°
28
75°
49°
29
75°
46°
30
73°
44°
31
72°
43°
1
75°
45°
2
80°
48°
3
82°
50°
4
81°
45°
5
67°
41°
6
73°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Boulder
Boulder's May 2026 forecast shows daily high temperatures ranging from 64° to 83°, with overnight lows between 41° and 50°. The average high for May is 75° 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 Boulder. See also: June | July | August.
