S
M
T
W
T
F
S
26
88°
71°
27
90°
67°
28
88°
67°
29
90°
68°
30
89°
69°
31
93°
73°
1
94°
72°
2
93°
72°
3
91°
68°
4
91°
68°
5
88°
69°
6
88°
68°
7
89°
69°
8
88°
69°
9
88°
71°
10
89°
72°
11
92°
72°
12
92°
71°
13
88°
72°
14
94°
67°
15
92°
66°
16
88°
66°
17
88°
67°
18
90°
70°
19
92°
67°
20
87°
65°
21
88°
66°
22
88°
70°
23
92°
70°
24
87°
69°
25
87°
70°
26
92°
70°
27
93°
69°
28
93°
70°
29
92°
69°
30
93°
64°
31
89°
64°
1
87°
68°
2
91°
69°
3
92°
68°
4
91°
68°
5
91°
67°
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 87° to 94°, with overnight lows between 64° and 73°. The average high for August is 90° with an average low of 69°. 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.
