S
M
T
W
T
F
S
30
85°
65°
31
84°
69°
1
92°
71°
2
86°
65°
3
85°
62°
4
81°
61°
5
80°
59°
6
80°
58°
7
78°
55°
8
77°
59°
9
79°
59°
10
77°
53°
11
74°
51°
12
73°
51°
13
73°
54°
14
72°
53°
15
78°
58°
16
78°
57°
17
76°
56°
18
74°
56°
19
77°
58°
20
77°
57°
21
76°
58°
22
78°
57°
23
77°
56°
24
76°
56°
25
76°
55°
26
77°
54°
27
76°
55°
28
76°
54°
29
74°
52°
30
72°
52°
1
73°
53°
2
73°
53°
3
72°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mount Pleasant
Mount Pleasant's September 2026 forecast shows daily high temperatures ranging from 72° to 92°, with overnight lows between 51° and 71°. The average high for September is 77° with an average low of 56°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Mount Pleasant. See also: October | November | December.