S
M
T
W
T
F
S
30
77°
40°
31
68°
42°
1
67°
49°
2
69°
50°
3
73°
42°
4
67°
46°
5
65°
48°
6
71°
48°
7
72°
41°
8
73°
36°
9
61°
37°
10
64°
40°
11
60°
38°
12
58°
40°
13
62°
39°
14
64°
45°
15
65°
45°
16
60°
36°
17
66°
37°
18
55°
42°
19
56°
44°
20
62°
39°
21
56°
40°
22
57°
33°
23
55°
39°
24
54°
40°
25
60°
36°
26
54°
33°
27
63°
40°
28
52°
28°
29
49°
30°
30
Hist. Avg.
57°
35°
1
Hist. Avg.
57°
35°
2
Hist. Avg.
56°
35°
3
Hist. Avg.
56°
34°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in The Key
The Key's September 2026 forecast shows daily high temperatures ranging from 49° to 77°, with overnight lows between 28° and 50°. The average high for September is 62° with an average low of 40°. 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 The Key. See also: October | November | December.
