S
M
T
W
T
F
S
26
83°
66°
27
91°
73°
28
84°
69°
29
69°
60°
30
63°
58°
1
65°
55°
2
76°
48°
3
80°
56°
4
82°
61°
5
90°
60°
6
67°
51°
7
74°
51°
8
75°
58°
9
90°
66°
10
81°
62°
11
78°
57°
12
84°
57°
13
91°
63°
14
91°
68°
15
90°
70°
16
87°
68°
17
87°
75°
18
91°
78°
19
90°
61°
20
78°
62°
21
78°
66°
22
87°
68°
23
80°
68°
24
87°
67°
25
88°
68°
26
86°
67°
27
78°
69°
28
86°
67°
29
89°
69°
30
90°
68°
31
84°
64°
1
81°
64°
2
84°
63°
3
82°
63°
4
83°
66°
5
91°
72°
6
88°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Charleston
Charleston's May 2026 forecast shows daily high temperatures ranging from 78° to 91°, with overnight lows between 63° and 73°. The average high for May is 85° with an average low of 67°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Charleston. See also: June | July | August.
