January weather forecast and climate
San Juan, PR

An old fort building and a view of the stunning San Juan city, Puerto Rico
An old fort building and a view of the stunning San Juan city, Puerto Rico

Weather in January

January, like December, in San Juan, Puerto Rico, is another warm winter month, with temperature in the range of an average low of 74.7°F (23.7°C) and an average high of 79.9°F (26.6°C).

Temperature

The coldest months are January and March, with an average high-temperature of 79.9°F (26.6°C).

Humidity

In January, the average relative humidity in San Juan is 77%.

Rainfall

In San Juan, in January, during 11.5 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In San Juan, Puerto Rico, during the entire year, the rain falls for 159.9 days and collects up to 12.01" (305mm) of precipitation.

Ocean temperature

In San Juan, the average seawater temperature in January is 79.7°F (26.5°C).
Note: For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

The average length of the day in January is 11.2h.

Sunshine

In San Juan, the average sunshine is 8.8h.

UV index

Months with the lowest UV index in San Juan are January through March and December, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV rays for average individuals.
Note: In January, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.
[Resources]

FAQ

What is the coldest month in San Juan?

The coldest months are January and March, with an average high-temperature of 79.9°F (26.6°C).

What is the temperature in January in San Juan?

In January, in San Juan, the average high-temperature is 79.9°F (26.6°C), and the average low-temperature is 74.7°F (23.7°C).

What is the average humidity in January in San Juan?

In January, the average relative humidity in San Juan is 77%.

How many days does it rain in January in San Juan?

In San Juan, Puerto Rico, in January, it is raining for 11.5 days, with typically 0.83" (21mm) of accumulated precipitation.

How warm is the water in January in San Juan?

In San Juan, Puerto Rico, the average seawater temperature in January is 79.7°F (26.5°C). For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

How many hours of daylight does San Juan have in January?

In San Juan, Puerto Rico, the average length of the day in January is 11.2h.

How long on average sun shines in January in San Juan?

In January, the average sunshine in San Juan, Puerto Rico, is 8.8h.

What is the month with the lowest UV index in San Juan?

Months with the lowest UV index in San Juan are January through March and December, with an average maximum UV index of 6.

What is the UV index intensity in January in San Juan?

The average daily maximum UV index in January in San Juan, Puerto Rico, is 6. A UV Index value of 6 to 7 symbolizes a high health threat from the exposure to the Sun's UV radiation.

Average temperature in January
San Juan, PR

Average temperature in January - San Juan, PR
  • Average high temperature in January: 79.9°F

The warmest month (with the highest average high temperature) is August (85.1°F).
Months with the lowest average high temperature are January and March (79.9°F).

  • Average low temperature in January: 74.7°F

Months with the highest average low temperature are August, September and October (79.2°F).
The coldest month (with the lowest average low temperature) is March (73.9°F).

[Resources]

Average pressure in January
San Juan, PR

Average pressure in January - San Juan, PR
  • Average pressure in January: 30.02"

Months with the highest atmospheric pressure are January and February (30.02").
The month with the lowest atmospheric pressure is October (29.9").

[Resources]

Average wind speed in January
San Juan, PR

Average wind speed in January - San Juan, PR
  • Average wind speed in January: 9.8mph

The windiest month (with the highest average wind speed) is July (10.7mph).
The calmest month (with the lowest average wind speed) is October (7.4mph).

[Resources]

Average humidity in January
San Juan, PR

Average humidity in January - San Juan, PR
  • Average humidity in January: 77%

Months with the highest relative humidity are May, June and July (79%).
Months with the lowest relative humidity are February and March (76%).

[Resources]

Average rainfall in January
San Juan, PR

Average rainfall in January - San Juan, PR
  • Average rainfall in January: 0.83"

The wettest month (with the highest rainfall) is November (1.57").
The driest month (with the least rainfall) is April (0.55").

[Resources]

Average rainfall days in January
San Juan, PR

Average rainfall days in January - San Juan, PR
  • Average rainfall days in January: 11.5 days

The month with the highest number of rainy days is November (16.1 days).
The month with the least rainy days is June (10.3 days).

[Resources]

Average sea temperature in January
San Juan, PR

Average sea temperature in January - San Juan, PR
  • Average sea temperature in January: 79.7°F

The best month for swimming (with the highest average sea temperature) is September (84.9°F).
The coldest month (with the lowest average sea temperature) is February (78.9°F).

[Resources]

Average daylight in January /
Average sunshine in January
San Juan, PR

Average daylight in January / Average sunshine in January - San Juan, PR
  • Average daylight in January: 11.2h

The month with the longest days is June (Average daylight: 13.2h).
The month with the shortest days is December (Average daylight: 11h).

  • Average sunshine in January: 8.8h

The month with the most sunshine is June (Average sunshine: 10.9h).
The month with the least sunshine is December (Average sunshine: 6.6h).

[Resources]

Average sunshine days in January
San Juan, PR

Average sunshine days in January - San Juan, PR
  • Average sunshine days in January: 11.1 days

The month with the most sunshine days is June (13.7 days).
The month with the least sunshine days is November (9.4 days).

[Resources]

Average UV index in January
San Juan, PR

Average UV index in January - San Juan, PR
  • Average UV index in January: 6

Months with the highest UV index are April, May, June, July, August, September, October and November (UV index 7).
Months with the lowest UV index are January, February, March and December (UV index 6).

[Resources]

Average cloud cover in January
San Juan, PR

Average cloud cover in January - San Juan, PR
  • Average cloud cover in January: 32

The month with the most cloud cover is December (Cloud cover 35).
The month with the least cloud cover is September (Cloud cover 26).

[Resources]

Average visibility in January
San Juan, PR

Average visibility in January - San Juan, PR
  • Average visibility in January: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

[Resources]