S
M
T
W
T
F
S
26
84°
66°
27
82°
71°
28
78°
71°
29
71°
62°
30
68°
56°
1
65°
54°
2
71°
48°
3
76°
47°
4
82°
62°
5
80°
62°
6
68°
54°
7
65°
51°
8
74°
56°
9
80°
60°
10
81°
60°
11
77°
58°
12
82°
62°
13
82°
64°
14
83°
62°
15
83°
62°
16
85°
64°
17
80°
62°
18
78°
66°
19
80°
65°
20
81°
66°
21
83°
61°
22
77°
59°
23
77°
59°
24
78°
60°
25
75°
60°
26
77°
61°
27
78°
60°
28
79°
61°
29
80°
64°
30
84°
68°
31
82°
69°
1
81°
69°
2
82°
65°
3
82°
69°
4
81°
70°
5
82°
71°
6
83°
71°
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 65° to 85°, with overnight lows between 51° and 71°. The average high for May is 79° with an average low of 63°. 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.
