S
M
T
W
T
F
S
26
98°
80°
27
95°
78°
28
96°
78°
29
96°
78°
30
97°
78°
1
96°
78°
2
95°
79°
3
94°
78°
4
95°
78°
5
94°
77°
6
96°
79°
7
95°
79°
8
94°
78°
9
95°
78°
10
96°
79°
11
96°
79°
12
95°
78°
13
96°
79°
14
96°
79°
15
95°
78°
16
96°
79°
17
96°
79°
18
95°
78°
19
96°
79°
20
96°
79°
21
95°
78°
22
95°
79°
23
94°
79°
24
94°
78°
25
93°
76°
26
94°
76°
27
92°
77°
28
92°
76°
29
93°
78°
30
92°
76°
31
92°
75°
1
93°
76°
2
94°
75°
3
92°
75°
4
92°
74°
5
93°
74°
6
93°
75°
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 92° to 98°, with overnight lows between 74° and 80°. The average high for May is 95° with an average low of 78°. 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.
