S
M
T
W
T
F
S
26
81°
53°
27
84°
57°
28
90°
58°
29
91°
59°
30
90°
59°
31
90°
58°
1
91°
59°
2
86°
58°
3
90°
59°
4
86°
58°
5
88°
58°
6
84°
57°
7
89°
57°
8
90°
56°
9
89°
56°
10
88°
46°
11
79°
45°
12
77°
47°
13
80°
50°
14
81°
48°
15
83°
49°
16
80°
48°
17
81°
44°
18
76°
46°
19
78°
52°
20
86°
55°
21
88°
55°
22
86°
54°
23
87°
44°
24
82°
41°
25
74°
43°
26
75°
48°
27
80°
54°
28
85°
53°
29
84°
53°
30
84°
47°
31
73°
47°
1
72°
52°
2
79°
47°
3
78°
46°
4
70°
42°
5
70°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Sun Prairie
Sun Prairie's August 2026 forecast shows daily high temperatures ranging from 70° to 91°, with overnight lows between 41° and 59°. The average high for August is 83° with an average low of 52°. 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 Sun Prairie. See also: September | October | November.