S
M
T
W
T
F
S
26
45°
21°
27
50°
23°
28
51°
25°
29
57°
32°
30
62°
28°
1
65°
29°
2
69°
33°
3
72°
34°
4
71°
38°
5
66°
43°
6
67°
35°
7
67°
39°
8
65°
35°
9
68°
35°
10
75°
35°
11
74°
45°
12
83°
38°
13
67°
39°
14
59°
30°
15
57°
32°
16
48°
27°
17
49°
22°
18
56°
32°
19
N/A
20
43°
29°
21
44°
30°
22
52°
38°
23
59°
44°
24
64°
38°
25
53°
31°
26
43°
29°
27
51°
32°
28
55°
33°
29
55°
32°
30
57°
34°
31
57°
33°
1
60°
36°
2
56°
35°
3
51°
32°
4
58°
39°
5
51°
38°
6
50°
32°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Helena
Helena's May 2026 forecast shows daily high temperatures ranging from 43° to 64°, with overnight lows between 29° and 44°. The average high for May is 53° with an average low of 34°. 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 Helena. See also: June | July | August.
