S
M
T
W
T
F
S
26
29°
17°
27
44°
16°
28
53°
22°
29
60°
24°
30
71°
29°
1
65°
37°
2
68°
33°
3
65°
43°
4
53°
37°
5
51°
27°
6
67°
30°
7
69°
42°
8
66°
38°
9
66°
44°
10
71°
44°
11
64°
41°
12
72°
36°
13
70°
44°
14
60°
42°
15
59°
39°
16
46°
33°
17
51°
29°
18
57°
30°
19
62°
31°
20
53°
39°
21
65°
34°
22
68°
44°
23
74°
38°
24
68°
44°
25
78°
43°
26
78°
48°
27
79°
57°
28
84°
53°
29
84°
58°
30
66°
43°
31
47°
43°
1
49°
42°
2
48°
40°
3
57°
41°
4
63°
44°
5
67°
43°
6
66°
44°
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 47° to 67°, with overnight lows between 40° and 44°. The average high for May is 58° with an average low of 43°. 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.
