Annual average weather for San Juan, Puerto Rico

Annual Temperature for San Juan

The hottest month in San Juan is September when the average maximum temperature is 35°, average temperature is 29° and average minimum temperature is 26°.

The coolest month in San Juan is January when the average maximum temperature is 28°, average temperature is 25° and average minimum temperature is 22°.

Annual Sunshine for San Juan

The longest days in San Juan are in June, with an average of 13.2 hours of daylight per day. December has the shortest days with an average of 11 hours of daylight per day.

The sunniest days in San Juan are in August which has the most hours of sunshine per day with an average of 8.7 hours of sunshine per day, making it a sunny month with few clouds. November has the least sunshine with an average of 7.3 hours of sunshine per day, making it a quite sunny month with some cloud cover.

The ultraviolet index is the highest in April when it reaches 13.6 and lowest in December when it reaches 7.5.

An ultraviolet index reading above 11 indicates an extreme risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 10 minutes. Take all precautions because unprotected skin and eyes can burn in minutes. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.

Annual Sea Temperature for San Juan

The warmest sea water temperatures in San Juan are found in September when they peak at 29° and lowest in February when they dip to 26°.

The sea is excellent for swimming all year round as the water temperature is very warm and ideal for relaxing and swimming for the whole day.

Annual Rainfall for San Juan

The wettest month in San Juan is August with 225.7cm of rain and December has the most days of rain with 25.3 days with some rain, a very wet time to visit the beach.

The driest month in San Juan is February with 70cm of rain and March has the fewest days of rain with 15.5 days with some rain, a wet time to visit the beach.

Annual Humidity for San Juan

The most humid month in San Juan is August with a dew point (an indicator of humidity) of 25° which is very uncomfortable and fairly oppressive unless you are on a beach. At night you would most likely require airconditioning.

The least humid month in San Juan is February with a dew point of 21° which is very humid and quite uncomfortable for most unless you are on a beach. At night you would most likely require a fan.

Annual Wind Speed for San Juan

The most windy month in San Juan is July when the average maximum windspeed is 34kmh and the average wind speed is 14kmh.

The least windy month in San Juan is October when the average maximum windspeed is 28kmh and the average wind speed is 9kmh.

Monthly Averages

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