San Juan
Puerto Rico, USA
Long-term weather forecast
Long-term weather forecast

April weather forecast and climate
San Juan, PR

An old fort building and a view of the stunning San Juan city, Puerto Rico, with a clear view of the calm waterfront
An old fort building and a view of the stunning San Juan city, Puerto Rico, with a clear view of the calm waterfront
April, the same as March, is a moderately hot spring month in San Juan, Puerto Rico, with average temperature fluctuating between 81.1°F (27.3°C) and 75.2°F (24°C).

Temperature

In San Juan, the average high-temperature is relatively the same as in March - a still moderately hot 81.1°F (27.3°C). In April, the average low-temperature is 75.2°F (24°C).

Heat index

The average heat index is calculated to a tropical 86.2°F (30.1°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'real feel', 'feels like', or 'apparent temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, pregnancy, metabolic differences, and wind affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

The average relative humidity in April is 77%.

Rainfall

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

Ocean temperature

In April, the average ocean temperature in San Juan is 80.4°F (26.9°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 San Juan is 12.6h.

Sunshine

In April, the average sunshine in San Juan, Puerto Rico, is 9.1h.

UV index

Months with the highest UV index in San Juan are April through November, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to the UV radiation for the ordinary person.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What is the temperature in April in San Juan?

The average high-temperature, in April, in San Juan, is 81.1°F (27.3°C), while the average low-temperature is 75.2°F (24°C). In April, the average heat index (a.k.a. 'felt air temperature', 'real feel'), that combines air temperature and relative humidity, is calculated to 86.2°F (30.1°C).

What is the average humidity in April in San Juan?

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

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

In San Juan, Puerto Rico, in April, it is raining for 12.4 days, with typically 0.55" (14mm) of accumulated precipitation.

What is the driest month in San Juan?

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

How warm is the water in April in San Juan?

In April, the average ocean temperature is 80.4°F (26.9°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

What is the average length of the day in April in San Juan?

The average length of the day in April is 12.6h.

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

In April, the average sunshine in San Juan is 9.1h.

When is the highest UV index in San Juan?

April through November, with an average maximum UV index of 7, are months with the highest UV index in San Juan, Puerto Rico.

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

In San Juan, the average daily maximum UV index in April is 7. A UV Index of 6 to 7 symbolizes a high health threat from unprotected exposure to the UV radiation.
Average temperature in April - San Juan, PR
  • Average high temperature in April: 27.3°C

The warmest month (with the highest average high temperature) is August (29.5°C).
Months with the lowest average high temperature are January and March (26.6°C).

  • Average low temperature in April: 24°C

Months with the highest average low temperature are August, September and October (26.2°C).
The coldest month (with the lowest average low temperature) is March (23.3°C).

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

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

Average rainfall in April - San Juan, PR
  • Average rainfall in April: 14mm

The wettest month (with the highest rainfall) is November (40mm).
The driest month (with the lowest rainfall) is April (14mm).

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 lowest number of rainy days is June (10.3 days).

Average sea temperature in April - San Juan, PR
  • Average sea temperature in April: 26.9°C

The best month for swimming (with the highest average sea temperature) is September (29.4°C).
Coldest months (with the lowest average sea temperature) are February and March (26.1°C).

Average daylight in April / Average sunshine in April - San Juan, PR
  • Average daylight in April: 12.6h

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

  • Average sunshine in April: 9.1h

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

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

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).