January weather forecast
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

The average relative humidity in January in San Juan is 77%.

Rainfall

In San Juan, during January, the rain falls for 11.5 days and regularly aggregates up to 0.83" (21mm) of precipitation. Throughout the year, there are 159.9 rainfall days, and 12.01" (305mm) of precipitation is accumulated.

Ocean temperature

In January, the average ocean temperature in San Juan is 79.7°F (26.5°C).
Note: Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

The average length of the day in January in San Juan, Puerto Rico, is 11h and 10min.
On the first day of January in San Juan, sunrise is at 6:56 am and sunset at 5:59 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:17 pm AST.

Sunshine

The average sunshine in January is 8.8h.

UV index

The months with the lowest UV index 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 risk from exposure to the Sun's UV radiation for average individuals.
Note: The daily maximum UV index of 6 in January interpret into the following advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.
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FAQ

What is the coldest month in San Juan?

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

What is the average humidity in January in San Juan?

The average relative humidity in January is 77%.

How much does it rain in San Juan in January?

In January, in San Juan, Puerto Rico, the rain falls for 11.5 days. Throughout January, 0.83" (21mm) of precipitation is accumulated.

What is the ocean temperature in January in San Juan?

In January, the average ocean temperature in San Juan is 79.7°F (26.5°C). Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

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

The average day length in January in San Juan, Puerto Rico, is 11h and 10min.

What time are sunrise and sunset in January in San Juan?

In January, on the first day of the month, sunrise is at 6:56 am and sunset at 5:59 pm. On the last day of the month, in San Juan, Puerto Rico, sunrise is at 6:57 am and sunset at 6:17 pm AST.

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

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

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

The months with the lowest UV index are January through March and December, with an average maximum UV index of 6.

How high is the UV index in January in San Juan?

In San Juan, the average daily maximum UV index in January is 6. A UV Index estimate of 6 to 7 represents a high health risk from 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).
The months with the lowest average high temperature are January and March (79.9°F).

  • Average low temperature in January: 74.7°F

The 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).

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Average pressure in January
San Juan, PR

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

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

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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).

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Average humidity in January
San Juan, PR

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

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

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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").

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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).

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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).

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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: 11h and 10min

The month with the longest days is June (Average daylight: 13h and 13min).
The month with the shortest days is December (Average daylight: 11h and 2min).

  • Average sunshine in January: 8h and 48min

The month with the most sunshine is June (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).

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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).

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Average UV index in January
San Juan, PR

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

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

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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).

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Average visibility in January
San Juan, PR

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

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

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