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

July 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
July, the same as June, in San Juan, Puerto Rico, is a hot summer month, with average temperature ranging between min 78.1°F (25.6°C) and max 88.7°F (31.5°C).

Temperature

In July, the average high-temperature is practically the same as in June - a still hot 88.7°F (31.5°C). The average low-temperature, in San Juan, Puerto Rico, is 78.1°F (25.6°C).

Heat index

In July, the average heat index is calculated to an extremely hot 105.8°F (41°C). Beware - heat cramps and heat exhaustion are very likely. Heatstroke is imminent with prolonged activity.
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', 'feels like', 'apparent temperature', or 'real feel', is a measure of how hot it feels when the actual air humidity is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (clothing, metabolic differences, differences in body mass, height, and shape), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. If the body can not disperse the excessive heat and body temperature reaches conditions of hyperthermia, above 99.5°F (37.5°C) to 100.9°F (38.3°C), thermal conditions are potentially life-threatening.

Humidity

The average relative humidity in San Juan, Puerto Rico, is 75.9%.

Rainfall

In San Juan, during 18.6 rainfall days, 7.1" (180mm) of precipitation is typically accumulated. Throughout the year, there are 198.5 rainfall days, and 70.6" (1794mm) of precipitation is accumulated.

Ocean temperature

In San Juan, in July, the average water temperature is 83.7°F (28.7°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 July is 13.1h.

Sunshine

March and July, with an average of 9.1h of sunshine, are months with the most sunshine.

UV index

March through September, with an average maximum UV index of 12, are months with the highest UV index in San Juan. A UV Index reading of 11, and higher, represents an excessive health risk from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: The average daily UV index of 12 in July transform into the following instructions:
Take all required precautions, as unprotected skin and eyes can burn in minutes. 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. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in July in San Juan?

The average high-temperature, in July, is 88.7°F (31.5°C), while the average low-temperature is 78.1°F (25.6°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), that factores the actual air temperature with the relative humidity, in July is evaluated at 105.8°F (41°C).

What is the average humidity in July in San Juan?

The average relative humidity in July is 75.9%.

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

In July, in San Juan, the rain falls for 18.6 days. Throughout July, 7.1" (180mm) of precipitation is accumulated.

How warm is the water in July in San Juan?

In July, the average ocean temperature in San Juan, Puerto Rico, is 83.7°F (28.7°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 July in San Juan?

In San Juan, the average length of the day in July is 13.1h.

What is the month with the most sunshine in San Juan?

March and July, with an average of 9.1h of sunshine, are months with the most sunshine in San Juan.

How many hours of sunshine does San Juan have in July?

The average sunshine in July in San Juan, Puerto Rico, is 9.1h.

When is the highest UV index in San Juan?

March through September, with an average maximum UV index of 12, are months with the highest UV index.

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

The average daily maximum UV index in July is 12. A UV Index estimate of 11, and higher, represents an extreme health vulnerability from the exposure to the Sun's UV radiation.
Average temperature in July - San Juan, PR
  • Average high temperature in July: 88.7°F

Warmest months (with the highest average high temperature) are August and September (89.2°F).
The month with the lowest average high temperature is January (83.2°F).

  • Average low temperature in July: 78.1°F

The month with the highest average low temperature is August (78.2°F).
Coldest months (with the lowest average low temperature) are January and February (72°F).

Average humidity in July - San Juan, PR
  • Average humidity in July: 75.9%

The month with the highest relative humidity is October (76.9%).
The month with the lowest relative humidity is March (71%).

Average rainfall in July - San Juan, PR
  • Average rainfall in July: 7.1"

The wettest month (with the highest rainfall) is August (7.7").
The driest month (with the lowest rainfall) is March (3.1").

Average rainfall days in July - San Juan, PR
  • Average rainfall days in July: 18.6 days

Months with the highest number of rainy days are November and December (19.6 days).
The month with the lowest number of rainy days is March (12.2 days).

Average sea temperature in July - San Juan, PR
  • Average sea temperature in July: 83.6°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 July / Average sunshine in July - San Juan, PR
  • Average daylight in July: 13.1h

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 July: 9.1h

Months with most sunshine are March and July (Average sunshine: 9.1h).
The month with least sunshine is November (Average sunshine: 6.7h).

Average UV index in July - San Juan, PR
  • Average UV index in July: 12

Months with the highest UV index are March, April, May, June, July, August and September (UV index 12).
Months with the lowest UV index are January and December (UV index 8).