S
M
T
W
T
F
S
26
87°
68°
27
87°
68°
28
89°
69°
29
91°
69°
30
90°
68°
31
90°
66°
1
87°
62°
2
86°
59°
3
79°
58°
4
78°
60°
5
81°
61°
6
82°
62°
7
85°
63°
8
87°
65°
9
86°
64°
10
87°
65°
11
88°
62°
12
85°
58°
13
Hist. Avg.
84°
63°
14
Hist. Avg.
84°
63°
15
Hist. Avg.
84°
63°
16
Hist. Avg.
83°
63°
17
Hist. Avg.
83°
62°
18
Hist. Avg.
83°
62°
19
Hist. Avg.
83°
62°
20
Hist. Avg.
83°
62°
21
Hist. Avg.
83°
62°
22
Hist. Avg.
83°
62°
23
Hist. Avg.
82°
62°
24
Hist. Avg.
82°
61°
25
Hist. Avg.
82°
61°
26
Hist. Avg.
82°
61°
27
Hist. Avg.
82°
61°
28
Hist. Avg.
81°
60°
29
Hist. Avg.
81°
60°
30
Hist. Avg.
81°
60°
31
Hist. Avg.
81°
60°
1
Hist. Avg.
80°
59°
2
Hist. Avg.
80°
59°
3
Hist. Avg.
80°
59°
4
Hist. Avg.
80°
58°
5
Hist. Avg.
79°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
August Weather in Onalaska
Onalaska's August 2026 forecast shows daily high temperatures ranging from 78° to 91°, with overnight lows between 58° and 69°. The average high for August is 86° with an average low of 64°. 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 Onalaska. See also: September | October | November.
