S
M
T
W
T
F
S
26
66°
46°
27
64°
35°
28
72°
41°
29
79°
46°
30
76°
46°
1
78°
47°
2
64°
45°
3
68°
40°
4
76°
42°
5
76°
45°
6
82°
51°
7
70°
46°
8
63°
36°
9
58°
38°
10
64°
33°
11
69°
36°
12
80°
40°
13
73°
47°
14
68°
44°
15
66°
46°
16
55°
36°
17
57°
32°
18
61°
33°
19
67°
35°
20
64°
38°
21
58°
41°
22
62°
35°
23
59°
37°
24
62°
35°
25
63°
38°
26
67°
40°
27
62°
38°
28
66°
41°
29
67°
47°
30
69°
43°
31
68°
43°
1
67°
50°
2
69°
50°
3
69°
49°
4
69°
52°
5
65°
55°
6
65°
52°
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 65° to 69°, with overnight lows between 49° and 55°. The average high for May is 67° with an average low of 51°. 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.
