S
M
T
W
T
F
S
30
91°
75°
31
92°
77°
1
94°
77°
2
89°
74°
3
89°
76°
4
90°
76°
5
88°
77°
6
88°
77°
7
88°
76°
8
90°
77°
9
89°
78°
10
90°
76°
11
89°
77°
12
89°
77°
13
90°
75°
14
89°
77°
15
90°
74°
16
87°
76°
17
86°
75°
18
88°
76°
19
87°
76°
20
87°
75°
21
86°
76°
22
87°
76°
23
87°
75°
24
88°
75°
25
86°
74°
26
87°
75°
27
87°
75°
28
88°
74°
29
86°
74°
30
86°
73°
1
85°
74°
2
85°
73°
3
86°
74°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Siesta Key
Siesta Key's September 2026 forecast shows daily high temperatures ranging from 85° to 90°, with overnight lows between 73° and 78°. The average high for September is 88° with an average low of 75°. 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 Siesta Key. See also: October | November | December.
