S
M
T
W
T
F
S
26
82°
63°
27
84°
66°
28
81°
64°
29
77°
59°
30
82°
55°
31
84°
61°
1
77°
70°
2
77°
63°
3
79°
59°
4
84°
55°
5
84°
61°
6
84°
64°
7
84°
70°
8
88°
68°
9
86°
63°
10
88°
68°
11
77°
64°
12
70°
64°
13
82°
63°
14
77°
69°
15
82°
72°
16
82°
66°
17
79°
60°
18
78°
63°
19
81°
62°
20
74°
57°
21
71°
54°
22
74°
57°
23
79°
62°
24
78°
61°
25
79°
61°
26
78°
60°
27
76°
67°
28
75°
56°
29
76°
57°
30
77°
59°
31
81°
63°
1
83°
64°
2
84°
64°
3
84°
63°
4
83°
63°
5
81°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Lewistown
Lewistown's August 2026 forecast shows daily high temperatures ranging from 71° to 84°, with overnight lows between 54° and 72°. The average high for August is 79° with an average low of 62°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Lewistown. See also: September | October | November.
