San Juan beaches are less crowded during the winter because of cool water temperatures. Credit: Wikimedia Creative Commons license

San Juan’s monthly weather has average temperatures ranging from the low 80s Fahrenheit in the winter to the high 80s in the summer. The dry season goes from January through April.

San Juan’s weather is similar to most other Caribbean islands with one exception: it doesn’t rain as much during the peak times of the hurricane season.

This popular cruise port in the eastern Caribbean has warm temperatures year round, although water temperatures are chilly at times in the winter.

San Juan also has distinct dry and rainy seasons. Although actual temperatures vary somewhat year to year, the averages offer some help for travel planners who want to know the best time to visit San Juan for weather.

San Juan Rainy Season

The Caribbean hurricane season officially runs from June 1 through Nov. 30 each year. The highest amount of rainfall usually hits in September and October with some destinations getting as much as 10 to 15 inches of rain in September.

San Juan’s rainy season averages about five to six inches each month from August through November, according to the U.S. National Weather Service. The number of days that it rains averages about 14 from July through December.

This historical New World city on the island of Puerto Rico also has a brief rainy season in May of another six inches of rain.

The winter and early spring months of January through March are a different story. Rainfall averages two to three inches a month. As a result, this time of year also makes San Juan a popular port of call for Caribbean cruises.

That leaves April and December, which are transition months between the dry season and the San Juan rainy season.

It rains about 12 to 15 days each month except for the dry season—especially February through April—when it rains an average of about nine days a month.

San Juan Monthly Temperatures

Temperatures are more predictable and stay within a narrow range throughout the year.

San Juan’s monthly temperatures range from the low 80s Fahrenheit during the winter to the high 80s during the summer. It ranges from the high 20s Celsius to low 30s.

Average monthly low temperatures range from the low 70s Fahrenheit to high 70s, mainly at night. In Celsius, it ranges from the low 20s to mid 20s.

Water temperatures are somewhat cool at times in combination with a wind chill factor and northern currents during the winter. So swimming is sometimes uncomfortable during cooler weather.

April is one of the best months to visit for a combination of warm temperatures and low risk of rain.

See weather in January | February | March | April |  May | June | July | August | September | October | November | December.