S
M
T
W
T
F
S
26
65°
47°
27
59°
40°
28
59°
36°
29
60°
37°
30
58°
36°
1
58°
34°
2
63°
37°
3
63°
42°
4
64°
41°
5
67°
42°
6
60°
38°
7
60°
37°
8
59°
39°
9
60°
37°
10
62°
46°
11
63°
49°
12
72°
46°
13
63°
43°
14
62°
41°
15
63°
41°
16
64°
42°
17
64°
43°
18
65°
41°
19
64°
41°
20
65°
42°
21
66°
48°
22
70°
48°
23
65°
44°
24
65°
43°
25
66°
44°
26
66°
45°
27
67°
47°
28
68°
46°
29
70°
50°
30
69°
51°
31
72°
50°
1
76°
52°
2
78°
56°
3
79°
57°
4
78°
54°
5
82°
57°
6
73°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Montana
Montana's May 2026 forecast shows daily high temperatures ranging from 58° to 82°, with overnight lows between 34° and 59°. The average high for May is 66° 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 Montana. See also: June | July | August.
