S
M
T
W
T
F
S
26
86°
76°
27
86°
77°
28
87°
78°
29
86°
78°
30
87°
77°
31
86°
76°
1
87°
77°
2
86°
78°
3
87°
78°
4
86°
77°
5
86°
76°
6
87°
78°
7
86°
77°
8
86°
78°
9
87°
78°
10
87°
77°
11
88°
78°
12
87°
78°
13
87°
77°
14
86°
77°
15
87°
76°
16
86°
76°
17
88°
75°
18
89°
76°
19
88°
76°
20
89°
75°
21
88°
77°
22
88°
77°
23
89°
76°
24
89°
75°
25
88°
76°
26
88°
76°
27
89°
75°
28
88°
77°
29
89°
78°
30
88°
76°
31
89°
77°
1
88°
76°
2
89°
77°
3
89°
76°
4
88°
76°
5
88°
75°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in San Juan
San Juan's August 2026 forecast shows daily high temperatures ranging from 86° to 89°, with overnight lows between 75° and 78°. The average high for August is 87° with an average low of 77°. 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 San Juan. See also: September | October | November.
