S
M
T
W
T
F
S
30
83°
75°
31
N/A
1
88°
75°
2
88°
76°
3
87°
77°
4
86°
76°
5
92°
77°
6
88°
74°
7
86°
74°
8
88°
75°
9
88°
73°
10
89°
73°
11
89°
73°
12
83°
71°
13
84°
70°
14
87°
76°
15
87°
76°
16
86°
75°
17
86°
74°
18
85°
74°
19
83°
73°
20
79°
73°
21
80°
72°
22
81°
73°
23
81°
73°
24
84°
72°
25
82°
73°
26
78°
73°
27
80°
72°
28
82°
72°
29
79°
71°
30
78°
71°
1
77°
70°
2
78°
71°
3
80°
70°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Johns Island
Johns Island's September 2026 forecast shows daily high temperatures ranging from 77° to 92°, with overnight lows between 70° and 77°. The average high for September is 84° with an average low of 73°. 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 Johns Island. See also: October | November | December.
