S
M
T
W
T
F
S
26
85°
63°
27
83°
62°
28
85°
63°
29
82°
60°
30
81°
66°
31
81°
65°
1
85°
65°
2
86°
66°
3
86°
67°
4
87°
66°
5
86°
64°
6
81°
60°
7
86°
66°
8
87°
64°
9
84°
66°
10
87°
65°
11
84°
61°
12
86°
65°
13
87°
66°
14
86°
61°
15
79°
58°
16
78°
57°
17
77°
62°
18
78°
65°
19
80°
65°
20
82°
64°
21
82°
64°
22
83°
63°
23
80°
60°
24
87°
58°
25
84°
63°
26
87°
63°
27
83°
62°
28
85°
63°
29
79°
56°
30
78°
55°
31
78°
58°
1
79°
62°
2
76°
63°
3
84°
63°
4
85°
62°
5
84°
59°
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 76° to 87°, with overnight lows between 55° and 67°. The average high for August is 83° 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 August weather will actually feel in Lewistown. See also: September | October | November.
