S
M
T
W
T
F
S
30
90°
77°
31
93°
77°
1
92°
76°
2
91°
77°
3
91°
77°
4
90°
76°
5
91°
77°
6
91°
77°
7
90°
76°
8
91°
77°
9
92°
77°
10
91°
76°
11
92°
76°
12
91°
75°
13
91°
75°
14
90°
76°
15
91°
76°
16
89°
75°
17
90°
76°
18
91°
75°
19
91°
75°
20
90°
74°
21
90°
76°
22
89°
75°
23
89°
75°
24
88°
73°
25
88°
72°
26
87°
73°
27
87°
74°
28
88°
74°
29
87°
73°
30
87°
74°
1
88°
74°
2
89°
73°
3
88°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Dismal Key
Dismal Key's September 2026 forecast shows daily high temperatures ranging from 87° to 93°, with overnight lows between 72° and 77°. The average high for September is 90° 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 Dismal Key. See also: October | November | December.
