S
M
T
W
T
F
S
26
101°
82°
27
100°
79°
28
99°
81°
29
100°
80°
30
101°
81°
31
101°
81°
1
100°
80°
2
101°
81°
3
101°
81°
4
99°
80°
5
101°
81°
6
101°
81°
7
100°
80°
8
100°
80°
9
101°
81°
10
100°
80°
11
101°
79°
12
101°
81°
13
100°
81°
14
101°
80°
15
101°
81°
16
100°
81°
17
100°
80°
18
98°
81°
19
99°
80°
20
100°
79°
21
100°
78°
22
98°
79°
23
96°
78°
24
99°
79°
25
100°
79°
26
99°
80°
27
100°
79°
28
99°
79°
29
98°
78°
30
96°
79°
31
96°
79°
1
98°
78°
2
98°
79°
3
97°
74°
4
96°
74°
5
92°
77°
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 92° to 101°, with overnight lows between 74° and 82°. The average high for August is 99° 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 San Juan. See also: September | October | November.
