S
M
T
W
T
F
S
30
89°
75°
31
88°
73°
1
87°
74°
2
87°
74°
3
88°
73°
4
89°
73°
5
88°
75°
6
89°
74°
7
90°
73°
8
89°
74°
9
90°
74°
10
90°
75°
11
89°
74°
12
90°
74°
13
90°
75°
14
89°
75°
15
88°
76°
16
88°
74°
17
87°
73°
18
87°
72°
19
88°
74°
20
87°
75°
21
86°
73°
22
87°
74°
23
87°
74°
24
88°
73°
25
86°
71°
26
87°
70°
27
87°
71°
28
88°
73°
29
88°
74°
30
87°
74°
1
88°
74°
2
Hist. Avg.
87°
73°
3
Hist. Avg.
87°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sebastian
Sebastian's September 2026 forecast shows daily high temperatures ranging from 86° to 90°, with overnight lows between 70° and 76°. The average high for September is 88° with an average low of 74°. 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 Sebastian. See also: October | November | December.
