S
M
T
W
T
F
S
26
65°
34°
27
58°
30°
28
60°
34°
29
64°
37°
30
65°
40°
1
70°
40°
2
67°
38°
3
61°
34°
4
60°
31°
5
62°
32°
6
69°
38°
7
72°
41°
8
73°
42°
9
74°
43°
10
72°
44°
11
76°
45°
12
75°
44°
13
74°
37°
14
63°
35°
15
64°
36°
16
68°
38°
17
73°
42°
18
70°
38°
19
67°
42°
20
67°
39°
21
76°
41°
22
78°
46°
23
79°
48°
24
78°
45°
25
79°
46°
26
80°
48°
27
80°
49°
28
83°
47°
29
81°
48°
30
83°
52°
31
85°
50°
1
83°
50°
2
84°
53°
3
84°
50°
4
75°
53°
5
84°
52°
6
82°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Longmont
Longmont's May 2026 forecast shows daily high temperatures ranging from 58° to 85°, with overnight lows between 30° and 53°. The average high for May is 73° with an average low of 42°. 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 Longmont. See also: June | July | August.
