S
M
T
W
T
F
S
26
91°
77°
27
90°
77°
28
92°
78°
29
91°
70°
30
92°
71°
1
89°
71°
2
90°
70°
3
89°
70°
4
88°
71°
5
90°
70°
6
88°
70°
7
89°
71°
8
88°
70°
9
89°
69°
10
87°
70°
11
88°
70°
12
87°
71°
13
89°
71°
14
87°
70°
15
89°
70°
16
90°
71°
17
89°
70°
18
89°
70°
19
90°
71°
20
89°
71°
21
89°
70°
22
90°
71°
23
89°
72°
24
89°
72°
25
88°
71°
26
88°
72°
27
89°
71°
28
90°
72°
29
92°
71°
30
94°
72°
31
92°
71°
1
92°
72°
2
93°
72°
3
92°
71°
4
94°
72°
5
94°
72°
6
93°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in San Juan
San Juan's May 2026 forecast shows daily high temperatures ranging from 87° to 94°, with overnight lows between 69° and 78°. The average high for May is 90° with an average low of 71°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in San Juan. See also: June | July | August.
