S
M
T
W
T
F
S
26
86°
68°
27
85°
66°
28
86°
64°
29
89°
67°
30
89°
70°
1
85°
69°
2
88°
67°
3
88°
67°
4
85°
68°
5
84°
68°
6
88°
68°
7
88°
68°
8
88°
69°
9
89°
69°
10
88°
71°
11
88°
70°
12
85°
71°
13
86°
70°
14
88°
72°
15
86°
72°
16
88°
71°
17
87°
71°
18
88°
70°
19
88°
70°
20
80°
72°
21
90°
69°
22
87°
71°
23
91°
70°
24
86°
70°
25
89°
73°
26
80°
69°
27
89°
68°
28
86°
68°
29
79°
65°
30
79°
66°
31
81°
66°
1
80°
66°
2
80°
64°
3
79°
66°
4
80°
65°
5
78°
64°
6
77°
63°
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 77° to 81°, with overnight lows between 63° and 66°. The average high for May is 79° with an average low of 65°. 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.
