S
M
T
W
T
F
S
26
88°
81°
27
87°
79°
28
88°
80°
29
88°
81°
30
89°
81°
31
88°
80°
1
88°
81°
2
89°
81°
3
88°
80°
4
88°
81°
5
89°
81°
6
88°
80°
7
88°
81°
8
89°
80°
9
88°
81°
10
89°
81°
11
90°
80°
12
90°
81°
13
91°
81°
14
90°
80°
15
90°
81°
16
91°
81°
17
90°
80°
18
90°
81°
19
91°
79°
20
86°
78°
21
91°
77°
22
91°
77°
23
91°
78°
24
90°
79°
25
91°
78°
26
90°
79°
27
90°
78°
28
89°
80°
29
88°
79°
30
89°
79°
31
89°
78°
1
90°
78°
2
90°
79°
3
89°
79°
4
90°
77°
5
90°
78°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Upper Keys
Upper Keys's August 2026 forecast shows daily high temperatures ranging from 86° to 91°, with overnight lows between 77° and 81°. The average high for August is 89° with an average low of 80°. 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 Upper Keys. See also: September | October | November.
