S
M
T
W
T
F
S
26
87°
68°
27
86°
66°
28
89°
69°
29
84°
65°
30
82°
69°
31
82°
64°
1
84°
70°
2
90°
70°
3
90°
69°
4
89°
69°
5
89°
68°
6
88°
70°
7
90°
69°
8
89°
70°
9
90°
68°
10
82°
65°
11
85°
67°
12
86°
68°
13
86°
67°
14
81°
61°
15
80°
60°
16
80°
60°
17
81°
61°
18
81°
63°
19
82°
65°
20
85°
67°
21
83°
66°
22
84°
66°
23
84°
65°
24
87°
58°
25
84°
60°
26
84°
64°
27
82°
65°
28
83°
61°
29
82°
60°
30
79°
59°
31
79°
62°
1
82°
62°
2
79°
55°
3
79°
53°
4
76°
54°
5
77°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Jerseyville
Jerseyville's August 2026 forecast shows daily high temperatures ranging from 76° to 90°, with overnight lows between 53° and 70°. The average high for August is 84° 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 Jerseyville. See also: September | October | November.