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°
41°
20
63°
40°
21
60°
40°
22
72°
44°
23
78°
50°
24
83°
53°
25
83°
51°
26
69°
47°
27
80°
49°
28
81°
51°
29
76°
47°
30
75°
51°
31
77°
52°
1
82°
56°
2
67°
45°
3
74°
51°
4
75°
51°
5
72°
50°
6
66°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Helena
Helena's May 2026 forecast shows daily high temperatures ranging from 60° to 83°, with overnight lows between 40° and 56°. The average high for May is 73° with an average low of 48°. 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.
