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

October 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
October, the same as September, in San Juan, Puerto Rico, is another tropical autumn month, with temperature in the range of an average low of 76.8°F (24.9°C) and an average high of 88.3°F (31.3°C).

Temperature

In San Juan, the average high-temperature in October is practically the same as in September - a still tropical 88.3°F (31.3°C). The average low-temperature, in San Juan, is 76.8°F (24.9°C).

Heat index

In October, the average heat index is appraised at a scorching 105.4°F (40.8°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. 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 'real feel', 'felt air temperature', 'apparent temperature', or 'feels like', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, pregnancy, clothing), 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 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.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. 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. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

With an average relative humidity of 76.9%, October is the most humid month.

Rainfall

In San Juan, during 17.7 rainfall days, 6.7" (171mm) of precipitation is typically accumulated. In San Juan, during the entire year, the rain falls for 198.5 days and collects up to 70.6" (1794mm) of precipitation.

Ocean temperature

In October, the average ocean temperature is 84.4°F (29.1°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 is 11.7h.

Sunshine

In San Juan, Puerto Rico, the average sunshine is 7.3h.

UV index

In October, the average daily maximum UV index is 10. A UV Index of 8 to 10 symbolizes a very high health vulnerability from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The average daily UV index of 10 transform into the following instructions:
Take extra precautions. Protection against sun damage is required. 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. 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. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in October in San Juan?

In San Juan, Puerto Rico, in October, the average high-temperature is 88.3°F (31.3°C), and the average low-temperature is 76.8°F (24.9°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), that factores the actual air temperature with the relative humidity, in October is estimated at 105.4°F (40.8°C).

What is the most humid month in San Juan?

October is the most humid month in San Juan, Puerto Rico, with an average relative humidity of 76.9%.

What is the average humidity in October in San Juan?

In San Juan, the average relative humidity in October is 76.9%.

How much does it rain in San Juan in October?

In San Juan, during October, the rain falls for 17.7 days and regularly aggregates up to 6.7" (171mm) of precipitation.

What is the water temperature in October in San Juan?

In October, the average ocean temperature in San Juan, Puerto Rico, is 84.4°F (29.1°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 October?

The average length of the day in October in San Juan is 11.7h.

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

In October, the average sunshine in San Juan is 7.3h.

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

In October, the average daily maximum UV index is 10. A UV Index of 8 to 10 symbolizes a very high health vulnerability from unprotected exposure to the UV radiation.
Average temperature in October - San Juan, PR
  • Average high temperature in October: 88.4°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 October: 76.9°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 October - San Juan, PR
  • Average humidity in October: 76.9%

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

Average rainfall in October - San Juan, PR
  • Average rainfall in October: 6.7"

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 October - San Juan, PR
  • Average rainfall days in October: 17.7 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 October - San Juan, PR
  • Average sea temperature in October: 84.4°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 October / Average sunshine in October - San Juan, PR
  • Average daylight in October: 11.7h

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 October: 7.3h

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 October - San Juan, PR
  • Average UV index in October: 10

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).