S
M
T
W
T
F
S
26
98°
82°
27
97°
82°
28
96°
83°
29
98°
83°
30
97°
79°
1
96°
82°
2
97°
82°
3
97°
81°
4
96°
79°
5
96°
81°
6
97°
82°
7
98°
79°
8
97°
81°
9
98°
84°
10
97°
81°
11
96°
83°
12
97°
83°
13
96°
84°
14
96°
84°
15
98°
83°
16
N/A
17
97°
81°
18
94°
80°
19
95°
79°
20
96°
80°
21
97°
81°
22
96°
80°
23
99°
81°
24
100°
81°
25
99°
82°
26
97°
81°
27
96°
81°
28
98°
82°
29
93°
79°
30
93°
79°
31
90°
78°
1
91°
78°
2
91°
79°
3
90°
79°
4
89°
78°
5
89°
78°
6
90°
77°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in San Juan
San Juan's May 2026 forecast shows daily high temperatures ranging from 89° to 100°, with overnight lows between 77° and 82°. The average high for May is 94° 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 May weather will actually feel in San Juan. See also: June | July | August.
