S
M
T
W
T
F
S
30
90°
82°
31
90°
82°
1
92°
82°
2
89°
83°
3
90°
83°
4
91°
78°
5
90°
83°
6
89°
83°
7
89°
83°
8
91°
81°
9
91°
83°
10
88°
82°
11
89°
84°
12
91°
80°
13
90°
80°
14
91°
81°
15
91°
81°
16
91°
79°
17
88°
78°
18
88°
78°
19
86°
80°
20
88°
81°
21
86°
81°
22
87°
82°
23
86°
79°
24
84°
79°
25
85°
79°
26
86°
80°
27
85°
79°
28
86°
79°
29
87°
78°
30
86°
77°
1
84°
78°
2
87°
80°
3
88°
80°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Duck Key
Duck Key's September 2026 forecast shows daily high temperatures ranging from 84° to 88°, with overnight lows between 77° and 82°. The average high for September is 86° with an average low of 79°. 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 Duck Key. See also: October | November | December.
