San Juan Weather

San Juan has a tropical monsoon climate and has an average temperature of 81.0 °F (27.2 °C) although 90 °F (32 °C) or higher temperatures are seen on an average 79 days annually, more commonly occurring during the wetter months of the northern summer, especially if the winds come from the south. In the winter, temperatures can drop to around 60 °F (16 °C), though the average winter low is 71 °F (22 °C). The coolest temperature officially recorded was 60 °F (16 °C) on March 3, 1957, and the hottest was 98 °F (37 °C) on October 9, 1981; the record cold daily maximum is 71 °F (22 °C) on February 4, 1935, while the record warm daily minimum is 83 °F (28 °C) on August 11, 1995, the most recent of four occasions. With a mean minimum of 67° F (19 C) send one is in USDA plant hardiness zone 13B the highest category. Rainfall is well-distributed throughout the year, but the months of January, February, and March are the driest; as March averages just 1.95 inches (49.5 mm) of rain, the city falls under the tropical monsoon category. Rainfall averages 56.35 inches (1,431.3 mm), falling on an average 198.5 days per year; despite this dampness, the city averages 2,970 hours of sunshine per year, or just over ⅔ of the possible total. Annual rainfall has historically ranged from 35.53 in (902 mm) in 1991 to 89.50 in (2,273 mm) in 2010.

Average Temperature
Jan
81 °F
27 °C
Feb
81 °F
27 °C
Mar
82 °F
28 °C
Apr
82 °F
28 °C
May
84 °F
29 °C
Jun
86 °F
30 °C
Jul
86 °F
30 °C
Aug
86 °F
30 °C
Sep
88 °F
31 °C
Oct
86 °F
30 °C
Nov
84 °F
29 °C
Dec
82 °F
28 °C
Humidity
Jan
80%
Feb
80%
Mar
77%
Apr
76%
May
79%
Jun
80%
Jul
79%
Aug
81%
Sep
82%
Oct
81%
Nov
81%
Dec
82%
Rain
Jan
47mm
Feb
52mm
Mar
56mm
Apr
81mm
May
107mm
Jun
74mm
Jul
107mm
Aug
106mm
Sep
210mm
Oct
140mm
Nov
70mm
Dec
52mm
Clouds
Jan
30%
Feb
32%
Mar
25%
Apr
27%
May
59%
Jun
41%
Jul
27%
Aug
40%
Sep
52%
Oct
42%
Nov
31%
Dec
41%
Air quality US AQI
Jan
52
Feb
13
Mar
20
Apr
30
May
40
Jun
47
Jul
76
Aug
46
Sep
59
Oct
35
Nov
33
Dec
43
Sun
Jan
7UVI
Feb
9UVI
Mar
10UVI
Apr
11UVI
May
8UVI
Jun
9UVI
Jul
10UVI
Aug
9UVI
Sep
9UVI
Oct
8UVI
Nov
7UVI
Dec
6UVI

See also