S
M
T
W
T
F
S
26
82°
66°
27
92°
72°
28
82°
64°
29
82°
58°
30
83°
61°
31
80°
65°
1
73°
64°
2
77°
61°
3
81°
59°
4
82°
61°
5
84°
66°
6
84°
67°
7
85°
69°
8
88°
68°
9
87°
67°
10
86°
67°
11
87°
67°
12
84°
66°
13
86°
66°
14
87°
65°
15
81°
61°
16
81°
63°
17
90°
70°
18
91°
70°
19
91°
69°
20
90°
69°
21
89°
68°
22
90°
68°
23
91°
69°
24
89°
69°
25
87°
68°
26
87°
68°
27
86°
67°
28
87°
67°
29
88°
68°
30
86°
66°
31
87°
67°
1
88°
66°
2
88°
66°
3
85°
64°
4
85°
65°
5
88°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Charleston
Charleston's August 2026 forecast shows daily high temperatures ranging from 73° to 91°, with overnight lows between 59° and 70°. The average high for August is 86° 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 Charleston. See also: September | October | November.
