S
M
T
W
T
F
S
26
91°
81°
27
92°
80°
28
93°
80°
29
94°
80°
30
91°
81°
31
91°
80°
1
93°
79°
2
91°
81°
3
91°
81°
4
90°
79°
5
90°
79°
6
90°
80°
7
89°
80°
8
89°
80°
9
89°
80°
10
88°
79°
11
88°
77°
12
89°
77°
13
88°
78°
14
89°
78°
15
88°
78°
16
89°
79°
17
86°
77°
18
87°
78°
19
87°
78°
20
86°
77°
21
87°
78°
22
87°
77°
23
88°
78°
24
88°
78°
25
89°
77°
26
87°
78°
27
87°
78°
28
88°
77°
29
88°
77°
30
87°
78°
31
86°
77°
1
87°
76°
2
86°
77°
3
86°
77°
4
87°
78°
5
87°
78°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Guaynabo
Guaynabo's August 2026 forecast shows daily high temperatures ranging from 86° to 90°, with overnight lows between 76° and 80°. The average high for August is 88° with an average low of 78°. 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 Guaynabo. See also: September | October | November.
