San Juan in May

In May, San Juan averages 30°C (86°F) during the day and 24°C (75°F) at night, with frequent rain — about 14 days of the month see precipitation (155 mm total).

Shoulder

Conditions are warm and beach-friendly. Plan for unsettled weather and bring rain gear.

May offers comfortable temperatures in San Juan, with some rain to plan around.

30°C
Avg high
24°C
Avg low
14
Rain days
155 mm
Rainfall

How May compares to the rest of the year in San Juan

6th
warmest month of the 12
4th
wettest month of the 12
11%
of yearly rainfall falls in May
13 h 0 min
daylight on the 15th

May is in the middle of the year for warmth in San Juan (6th of 12) and moderately rainy compared to the rest of the year (4th of 12). Daytime temperature matches the city's annual average. May runs 1°C warmer than April (29°C) and warms a further 1°C into June (31°C).

May sunrise & sunset in San Juan

🌅
Sunrise (15th)
5:50 AM
🌇
Sunset (15th)
6:50 PM
Day length
13 h 0 min

Times shown for San Juan local time (America/Puerto_Rico), calculated for the 15th of May. They shift by a few minutes day to day across the month.

Photography light in San Juan — May

Golden-hour and blue-hour windows for the 15th of May, in San Juan's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:50 AM – 5:30 AM
🌄 Golden hour (AM)
5:30 AM – 6:30 AM
🌇 Golden hour (PM)
6:10 PM – 7:10 PM
🌆 Blue hour (PM)
7:10 PM – 7:50 PM
Milky Way galactic core
Good
Galactic core is up but lower on the horizon; head well outside city limits for a clean view.

📅 When to book — San Juan in May

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on May's tier (Shoulder) and San Juan's popularity.

✈ Flights — lead time
6-10 weeks
Sweet spot for value. Major fare-sales (US: Black Friday, EU: post-Easter) hit hardest in shoulder months for shoulder travel.
🏨 Lodging — lead time
4-8 weeks
Lots of selection. Look for shoulder-season packages — many hotels add value (free breakfast, spa credit) to fill rooms.

Crowds & pricing — May in San Juan

Shoulder

San Juan is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.

Sun & mosquito risk — May in San Juan

☀️ UV Index (noon, 15th)
13
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in San Juan — May

28.5°C (83°F)
bath-warm
tropical and comfortable for hours

Across the year San Juan's sea swings from 26.5°C (February) to 30.4°C (October) — May sits at 28.5°C.

San Juan in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 28°C / 82°F 21°C / 70°F 75 mm 11
February 28°C / 82°F 21°C / 70°F 55 mm 9
March 29°C / 84°F 22°C / 72°F 55 mm 9
April 29°C / 84°F 23°C / 73°F 110 mm 11
May 30°C / 86°F 24°C / 75°F 155 mm 14
June 31°C / 88°F 25°C / 77°F 130 mm 14
July 31°C / 88°F 25°C / 77°F 150 mm 16
August 32°C / 90°F 25°C / 77°F 165 mm 16
September 31°C / 88°F 25°C / 77°F 145 mm 15
October 31°C / 88°F 24°C / 75°F 130 mm 13
November 30°C / 86°F 23°C / 73°F 140 mm 13
December 29°C / 84°F 22°C / 72°F 110 mm 12

Other cities with similar May weather

🌍 See the full ranked list of climate twins for San Juan in May →

Frequently asked questions

How hot is San Juan in May?

In May, San Juan averages a high of 30°C (86°F) and a low of 24°C (75°F) — generally hot.

Does it rain a lot in San Juan in May?

May can be fairly wet in San Juan, with about 14 rainy days on average.

Is May a good time to visit San Juan?

May is hot but on the rainy side. It suits travelers who are comfortable with hot weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for San Juan in May?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full May packing list for San Juan for a complete, climate-based checklist.

Open San Juan on the interactive map

Check the live 10-day forecast and sunrise/sunset.