S
M
T
W
T
F
S
26
84°
64°
27
83°
65°
28
83°
65°
29
84°
67°
30
84°
68°
31
85°
67°
1
86°
65°
2
85°
66°
3
86°
65°
4
87°
63°
5
85°
63°
6
84°
64°
7
85°
70°
8
Hist. Avg.
89°
71°
9
Hist. Avg.
89°
70°
10
Hist. Avg.
89°
70°
11
Hist. Avg.
89°
70°
12
Hist. Avg.
89°
70°
13
Hist. Avg.
89°
70°
14
Hist. Avg.
89°
70°
15
Hist. Avg.
89°
70°
16
Hist. Avg.
89°
70°
17
Hist. Avg.
88°
70°
18
Hist. Avg.
88°
69°
19
Hist. Avg.
88°
69°
20
Hist. Avg.
88°
69°
21
Hist. Avg.
88°
69°
22
Hist. Avg.
88°
69°
23
Hist. Avg.
88°
68°
24
Hist. Avg.
88°
68°
25
Hist. Avg.
87°
68°
26
Hist. Avg.
87°
68°
27
Hist. Avg.
87°
67°
28
Hist. Avg.
87°
67°
29
Hist. Avg.
86°
67°
30
Hist. Avg.
86°
67°
31
Hist. Avg.
86°
66°
1
Hist. Avg.
86°
66°
2
Hist. Avg.
86°
66°
3
Hist. Avg.
85°
65°
4
Hist. Avg.
85°
65°
5
Hist. Avg.
85°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
August Weather in St. Charles
St. Charles's August 2026 forecast shows daily high temperatures ranging from 83° to 87°, with overnight lows between 63° and 70°. The average high for August is 85° with an average low of 66°. 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 St. Charles. See also: September | October | November.
