S
M
T
W
T
F
S
30
92°
75°
31
93°
76°
1
93°
76°
2
92°
77°
3
91°
78°
4
92°
77°
5
93°
79°
6
92°
79°
7
89°
77°
8
88°
76°
9
91°
77°
10
94°
77°
11
93°
75°
12
93°
77°
13
87°
76°
14
93°
78°
15
93°
79°
16
92°
78°
17
92°
76°
18
92°
75°
19
91°
73°
20
89°
73°
21
91°
73°
22
92°
75°
23
89°
75°
24
N/A
25
85°
70°
26
85°
67°
27
85°
66°
28
86°
69°
29
87°
71°
30
89°
72°
1
91°
74°
2
89°
75°
3
92°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Keys
Keys's September 2026 forecast shows daily high temperatures ranging from 89° to 92°, with overnight lows between 72° and 75°. The average high for September is 90° 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 Keys. See also: October | November | December.
