S
M
T
W
T
F
S
26
79°
52°
27
77°
55°
28
61°
50°
29
61°
43°
30
64°
37°
1
61°
37°
2
61°
43°
3
73°
39°
4
81°
54°
5
61°
46°
6
59°
41°
7
68°
39°
8
64°
52°
9
81°
50°
10
68°
46°
11
77°
45°
12
81°
54°
13
73°
50°
14
75°
48°
15
84°
54°
16
81°
64°
17
86°
68°
18
77°
64°
19
72°
54°
20
66°
50°
21
72°
52°
22
70°
59°
23
79°
55°
24
81°
59°
25
81°
54°
26
82°
54°
27
88°
63°
28
88°
61°
29
N/A
30
80°
64°
31
81°
65°
1
84°
62°
2
86°
58°
3
86°
62°
4
88°
66°
5
85°
66°
6
83°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Lewistown
Lewistown's May 2026 forecast shows daily high temperatures ranging from 80° to 88°, with overnight lows between 58° and 66°. The average high for May is 84° 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 Lewistown. See also: June | July | August.
