S
M
T
W
T
F
S
28
88°
74°
29
89°
74°
30
90°
74°
31
83°
74°
1
81°
74°
2
81°
73°
3
82°
73°
4
87°
72°
5
83°
73°
6
82°
74°
7
86°
73°
8
83°
73°
9
85°
74°
10
86°
74°
11
85°
75°
12
86°
74°
13
84°
74°
14
85°
74°
15
86°
74°
16
88°
74°
17
88°
74°
18
90°
74°
19
89°
74°
20
89°
73°
21
87°
73°
22
88°
72°
23
87°
71°
24
87°
71°
25
88°
72°
26
86°
73°
27
86°
74°
28
87°
73°
29
88°
73°
30
88°
72°
31
87°
73°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
January Weather in San Juan
San Juan's January 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for January is ° with an average low of °. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how January weather will actually feel in San Juan. See also: February | March | April.
