S
M
T
W
T
F
S
26
35°
26°
27
51°
19°
28
57°
28°
29
60°
28°
30
66°
33°
1
75°
40°
2
67°
41°
3
72°
42°
4
53°
34°
5
50°
32°
6
68°
48°
7
72°
44°
8
74°
44°
9
65°
41°
10
66°
41°
11
67°
42°
12
71°
43°
13
72°
44°
14
73°
49°
15
57°
33°
16
58°
35°
17
62°
38°
18
66°
44°
19
60°
42°
20
57°
42°
21
59°
40°
22
61°
38°
23
58°
42°
24
60°
37°
25
60°
36°
26
65°
40°
27
70°
43°
28
71°
46°
29
63°
45°
30
61°
44°
31
65°
46°
1
67°
47°
2
63°
44°
3
69°
47°
4
67°
48°
5
64°
48°
6
64°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Great Falls
Great Falls's May 2026 forecast shows daily high temperatures ranging from 50° to 75°, with overnight lows between 32° and 50°. The average high for May is 65° with an average low of 42°. 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 Great Falls. See also: June | July | August.
