S
M
T
W
T
F
S
30
85°
74°
31
84°
75°
1
86°
74°
2
88°
75°
3
88°
73°
4
85°
71°
5
86°
71°
6
84°
72°
7
85°
71°
8
86°
72°
9
87°
74°
10
87°
71°
11
88°
72°
12
88°
70°
13
87°
70°
14
87°
71°
15
86°
70°
16
87°
71°
17
85°
73°
18
86°
74°
19
85°
73°
20
85°
73°
21
83°
72°
22
83°
72°
23
Hist. Avg.
84°
71°
24
Hist. Avg.
84°
70°
25
Hist. Avg.
84°
70°
26
Hist. Avg.
84°
70°
27
Hist. Avg.
84°
70°
28
Hist. Avg.
83°
69°
29
Hist. Avg.
83°
69°
30
Hist. Avg.
83°
69°
1
Hist. Avg.
83°
68°
2
Hist. Avg.
82°
68°
3
Hist. Avg.
82°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in St. Simons
St. Simons's September 2026 forecast shows daily high temperatures ranging from 83° to 88°, with overnight lows between 70° and 75°. The average high for September is 86° with an average low of 72°. 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 St. Simons. See also: October | November | December.
