S
M
T
W
T
F
S
26
90°
81°
27
91°
80°
28
91°
81°
29
92°
80°
30
90°
82°
31
90°
82°
1
92°
81°
2
91°
82°
3
92°
82°
4
90°
81°
5
90°
81°
6
88°
80°
7
90°
82°
8
90°
82°
9
91°
81°
10
90°
82°
11
90°
82°
12
92°
81°
13
92°
80°
14
91°
80°
15
93°
81°
16
93°
79°
17
91°
80°
18
92°
80°
19
91°
79°
20
91°
80°
21
92°
81°
22
93°
80°
23
93°
79°
24
92°
81°
25
91°
81°
26
92°
80°
27
92°
80°
28
91°
81°
29
91°
81°
30
92°
80°
31
90°
80°
1
91°
79°
2
89°
80°
3
90°
80°
4
91°
79°
5
92°
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 88° to 93°, with overnight lows between 79° and 82°. The average high for August is 91° 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.
