San Juan in August

In August, San Juan averages 32°C (90°F) during the day and 25°C (77°F) at night, with frequent rain — about 16 days of the month see precipitation (165 mm total).

Shoulder

Conditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.

It's peak hurricane season in San Juan during August. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

32°C
Avg high
25°C
Avg low
16
Rain days
165 mm
Rainfall

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

1st
warmest month of the 12
2nd
wettest month of the 12
12%
of yearly rainfall falls in August
12 h 46 min
daylight on the 15th

August is one of the warmest months in San Juan (1st of 12) and one of the wettest months (2nd of 12). Daytime temperature runs 2°C above the annual average (30°C). August runs 1°C warmer than July (31°C) and cools 1°C in September (31°C).

August sunrise & sunset in San Juan

🌅
Sunrise (15th)
6:06 AM
🌇
Sunset (15th)
6:51 PM
Day length
12 h 46 min

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

Photography light in San Juan — August

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

🌅 Blue hour (AM)
5:06 AM – 5:46 AM
🌄 Golden hour (AM)
5:46 AM – 6:46 AM
🌇 Golden hour (PM)
6:11 PM – 7:11 PM
🌆 Blue hour (PM)
7:11 PM – 7:51 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near San Juan.

📅 When to book — San Juan in August

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 August'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. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 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 — August 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.

Why this tier: Northern Hemisphere summer holidays peak hazard season (1 active)

Sun & mosquito risk — August in San Juan

☀️ UV Index (noon, 15th)
12.9
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 — August

29.7°C (85°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) — August sits at 29.7°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 August weather

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

Frequently asked questions

How hot is San Juan in August?

In August, San Juan averages a high of 32°C (90°F) and a low of 25°C (77°F) — generally hot.

Does it rain a lot in San Juan in August?

August is quite rainy in San Juan, with about 16 rainy days on average.

Is August a good time to visit San Juan?

August 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 August?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full August 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.