S
M
T
W
T
F
S
27
89°
76°
28
90°
80°
29
85°
72°
30
85°
77°
1
83°
74°
2
88°
81°
3
87°
80°
4
90°
79°
5
90°
80°
6
90°
79°
7
90°
77°
8
90°
77°
9
90°
81°
10
91°
82°
11
90°
77°
12
90°
80°
13
89°
78°
14
88°
78°
15
90°
80°
16
90°
76°
17
90°
76°
18
85°
79°
19
85°
77°
20
85°
74°
21
83°
76°
22
82°
74°
23
83°
75°
24
82°
75°
25
84°
77°
26
82°
78°
27
83°
74°
28
84°
76°
29
83°
75°
30
84°
76°
31
86°
75°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
October Weather in Key Biscayne
Key Biscayne's October 2026 forecast shows daily high temperatures ranging from 82° to 86°, with overnight lows between 74° and 79°. The average high for October is 84° with an average low of 76°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how October weather will actually feel in Key Biscayne. See also: November | December | January.