San Juan Weather in May
May in San Juan typically sees daytime highs of 30°C (86°F) and nighttime lows of 24°C (75°F). Rainfall is also possible this month, so it's worth packing an umbrella.
Rainfall in San Juan in May
Historically, May sees about 16 days of rain, with a monthly average of 134 mm (5.3 in). This month brings frequent, heavy showers. Both the number of wet days and the rainfall totals are on the high side.
Temperature in San Juan in May
Daytime temperatures in San Juan reach 30°C (86°F) in May, dropping to 24°C (75°F) at night. Sunshine and humidity can make it feel even warmer than the raw temperature suggests. With overnight lows of 24°C (75°F), evenings and nights remain warm. Light clothing and an open window or fan can help you sleep comfortably.
Sunshine in San Juan in May
Expect a lot of sunshine this month, with about 255 hours of sun. These sunny conditions add to the overall experience.
Wind Speed in San Juan in May
May has wind speeds averaging 3 m/s (6 knots). You can expect comfortable light winds that steadily move flags and feel mild throughout the day. Since this is an average, daily conditions vary from gentle winds to more active breezes.
Average water temperature in May
The water temperature is 27°C (81°F), which most people find very comfortable. A good month for swimming and water sports.May in San Juan can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our San Juan's climate page.
San Juan Temperature in May
Min Temperature
24°C (75°F)
Max Temperature
30°C (86°F)
Water Temperature
27°C (81°F)
Chance of Rain
53%
Precipitation
134 mm (5.3 in)
Rainy days
16 days
Humidity
75%
Windspeed
3 m/s (6 knots)
Sunshine
255 hours
Percentage Sunshine
63%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in San Juan typically stay consistent throughout May, with daily highs averaging around 30°C (86°F). Nights are warm, with lows around 24°C (75°F).
Average temperatures in May
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in May
Historical weather for San Juan in May
Browse day-by-day weather records for San Juan spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Juan historical weather extremes in May
Based on 50 years of weather observations in San Juan between 1976 and 2026, these are the recorded extremes.
- On May 11, 1980, temperatures climbed to 36°C (97°F), marking the warmest May day on record.
- On May 23, 2004, San Juan saw its coldest May day with temperatures maxing out at 24°C (75°F).
- The lowest overnight temperature recorded in May was 21°C (70°F) (May 7, 1986).
Best Places in Puerto Rico in May
Find out more about the weather in Puerto Rico and which places have the best travel conditions in this month. See all of Puerto Rico in May →
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What to Wear in San Juan in May
Warm weather calls for comfortable, breathable clothing in May. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. The water temperature sits at about 27°C (81°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in San Juan in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our San Juan's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full San Juan climate overview or explore weather in Puerto Rico.
