S
M
T
W
T
F
S
26
94°
78°
27
92°
75°
28
91°
78°
29
94°
79°
30
96°
80°
31
96°
81°
1
94°
74°
2
91°
78°
3
93°
73°
4
92°
77°
5
90°
78°
6
88°
75°
7
91°
79°
8
92°
82°
9
92°
82°
10
93°
84°
11
94°
83°
12
94°
80°
13
94°
78°
14
96°
82°
15
93°
80°
16
94°
82°
17
95°
80°
18
100°
82°
19
96°
76°
20
93°
79°
21
94°
81°
22
89°
83°
23
88°
82°
24
89°
84°
25
87°
81°
26
87°
82°
27
87°
83°
28
88°
82°
29
90°
81°
30
89°
82°
31
88°
80°
1
89°
80°
2
88°
81°
3
87°
80°
4
91°
81°
5
90°
80°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Key Biscayne
Key Biscayne's August 2026 forecast shows daily high temperatures ranging from 87° to 91°, with overnight lows between 80° and 84°. The average high for August is 88° with an average low of 81°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Key Biscayne. See also: September | October | November.
