S
M
T
W
T
F
S
26
54°
37°
27
52°
37°
28
63°
37°
29
59°
36°
30
48°
39°
1
63°
32°
2
72°
39°
3
N/A
4
68°
40°
5
41°
29°
6
37°
29°
7
66°
43°
8
70°
45°
9
71°
43°
10
70°
44°
11
78°
48°
12
77°
52°
13
79°
52°
14
79°
55°
15
82°
52°
16
78°
51°
17
70°
45°
18
75°
48°
19
70°
40°
20
74°
43°
21
67°
40°
22
69°
45°
23
76°
48°
24
67°
44°
25
67°
41°
26
68°
43°
27
69°
47°
28
68°
45°
29
69°
49°
30
69°
48°
31
68°
47°
1
71°
45°
2
74°
46°
3
77°
47°
4
76°
48°
5
73°
48°
6
74°
50°
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 37° to 82°, with overnight lows between 29° and 55°. The average high for May is 70° with an average low of 45°. 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.
