S
M
T
W
T
F
S
26
91°
81°
27
89°
76°
28
89°
83°
29
91°
83°
30
92°
84°
31
91°
83°
1
92°
82°
2
90°
84°
3
92°
83°
4
91°
82°
5
90°
81°
6
90°
83°
7
91°
83°
8
90°
82°
9
92°
82°
10
91°
83°
11
90°
83°
12
89°
82°
13
89°
83°
14
90°
83°
15
88°
82°
16
88°
83°
17
88°
83°
18
88°
82°
19
88°
83°
20
88°
83°
21
88°
82°
22
89°
82°
23
88°
83°
24
88°
79°
25
89°
83°
26
88°
83°
27
89°
82°
28
89°
82°
29
88°
82°
30
88°
82°
31
89°
82°
1
88°
81°
2
88°
82°
3
89°
82°
4
89°
81°
5
88°
82°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Key West
Key West's August 2026 forecast shows daily high temperatures ranging from 88° to 92°, with overnight lows between 79° and 84°. The average high for August is 89° with an average low of 82°. 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 West. See also: September | October | November.