April weather forecast
San Juan, PR

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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 April

April invites a new chapter of weather in San Juan. The increase to 81.1°F (27.3°C) in average high temperatures accompanies a rise in sea temperatures to 80.5°F (26.9°C), signaling the onset of a warmer climate. Sunshine hours continue to increase, yet cloud cover remains relatively constant. Notably, daylight hours exceed half the day for the first time in the year, averaging 12.6 hours. This progression into the warmer months further enhances the city’s appeal to sightseers and tourists.

Temperature

Upon the beginning of April, San Juan's high-temperatures register at a still warm 81.1°F (27.3°C), closely mirroring the preceding month. San Juan reports an average low temperature of 75.2°F (24°C) in April, a minor decrease from the day's highs.

Heat index

The heat index value during April is evaluated at a tropical 86°F (30°C). Exhaustion becomes probable with enduring exposure and activity, potentially causing heat cramps.
Research indicates the heat index considers values in shaded locales and with light winds. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', integrates the air's temperature and its humidity to showcase the felt temperature by people. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.

Humidity

The average relative humidity in April is 77%.

Rainfall

April is the month with the least rainfall in San Juan. Rain falls for 12.4 days and accumulates 0.55" (14mm) of precipitation.

Ocean temperature

In April, the average ocean temperature is 80.4°F (26.9°C).
Note: Water temperature ranging between 77°F (25°C) and 84.2°F (29°C) is considered very warm and pleasing for everyone. It allows for enjoyable water activities over extended periods without discomfort.

Daylight

The average length of the day in April is 12h and 34min.
On the first day of April, sunrise is at 6:17 am and sunset at 6:38 pm. On the last day of the month, sunrise is at 5:57 am and sunset at 6:45 pm AST.

Sunshine

The average sunshine in April is 9.1h.

UV index

The months with the highest UV index are April through November, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In April, the maximum UV index of 7 transforms into these recommendations:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Take warning! Reflective sand and water surfaces intensify the Sun's UV rays.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are April temperatures?

San Juan in April has an average high-temperature of 81.1°F (27.3°C) and an average low-temperature of 75.2°F (24°C). In April, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 86°F (30°C).

What is the average humidity in April?

In April, the average relative humidity is 77%.

What is the driest month?

The month with the least rainfall is April, when the rain falls for 12.4 days and typically collects 0.55" (14mm) of precipitation.

How much does it rain in April?

In April, the rain falls for 12.4 days. Throughout April, 0.55" (14mm) of precipitation is accumulated.

How warm is the water in April in San Juan?

In San Juan, in April, the average water temperature is 80.4°F (26.9°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.

What is the average length of the day in April?

In San Juan, the average day length in April is 12h and 34min.

When are sunrise and sunset in April?

On the first day of April, sunrise is at 6:17 am and sunset at 6:38 pm. On the last day of the month, sunrise is at 5:57 am and sunset at 6:45 pm AST.

How long on average sun shines in April?

In April, the average sunshine duration is 9.1h.

When is the highest UV index?

April through November, with an average maximum UV index of 7, are months with the highest UV index.

What is the UV index intensity in April?

In April, the average daily maximum UV index is 7. A UV Index reading of 6 to 7 represents a high hazard to health from exposure to the Sun's UV radiation.

Average temperature in April
San Juan, PR

Average temperature in April - San Juan, PR
  • Average high temperature in April: 81.1°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 April: 75.2°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).

Average pressure in April
San Juan, PR

Average pressure in April - San Juan, PR
  • Average pressure in April: 29.99"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).

Average wind speed in April
San Juan, PR

Average wind speed in April - San Juan, PR
  • Average wind speed in April: 9.4mph

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).

Average humidity in April
San Juan, PR

Average humidity in April - San Juan, PR
  • Average humidity in April: 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%).

Average rainfall in April
San Juan, PR

Average rainfall in April - San Juan, PR
  • Average rainfall in April: 0.55"

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

Average rainfall days in April
San Juan, PR

Average rainfall days in April - San Juan, PR
  • Average rainfall days in April: 12.4 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).

Average sea temperature in April
San Juan, PR

Average sea temperature in April - San Juan, PR
  • Average sea temperature in April: 80.5°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).

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

Average daylight in April / Average sunshine in April - San Juan, PR
  • Average daylight in April: 12h and 4min

The month with the longest days is June (Average daylight: 13h and 12min).
The month with the shortest days is December (Average daylight: 11h and 0min).

  • Average sunshine in April: 9h and 1min

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).

Average sunshine days in April
San Juan, PR

Average sunshine days in April - San Juan, PR
  • Average sunshine days in April: 11 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).

Average UV index in April
San Juan, PR

Average UV index in April - San Juan, PR
  • Average UV index in April: 7

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).

Average cloud cover in April
San Juan, PR

Average cloud cover in April - San Juan, PR
  • Average cloud cover in April: 30

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

Average visibility in April
San Juan, PR

Average visibility in April - San Juan, PR
  • Average visibility in April: 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).

San Juan, Puerto Rico, USA

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