August 9 is generally a great time to visit San Juan. While there is a slight chance of rain (34%), showers are usually brief. Expect comfortable 31°C weather. It's a lively time to explore San Juan, with most attractions operating at full capacity.
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Essential Travel Info for San Juan
Currency
USD
$ United States dollar
Language
English
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Driving
Right side
San Juan Weather Forecast for August 9
"Warm & Sunny. Expect average highs of 31.2°C. 34% chance of rain."
What to Wear in San Juan in August
Based on historical data for August 9, San Juan typically experiences temperatures between 25.1°C and 31.2°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 34% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for San Juan
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
31.2°C
Daytime Peak
Average Low
25.1°C
Nighttime Low
Feels Like
40.8°C
🔥 Heat index effect
Rain Chance
34%
Avg 1.8mm if it rains
Cloud Cover
54%
Light drizzle
Pressure
1015.8 hPa
Low volatility
San Juan Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 95% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
06:00 - 10:00
16:00 - 18:00
Type I-II
🔴 15 min to burn
Type III-IV
🟡 23 min to burn
Type V-VI
🟢 38 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
26.9°C
Humid/Sticky
Heat Index
40.8°C
Feels hotter
😕 Best outdoor time:
Early morning (6-9 AM) or evening (after 6 PM)
Marine Conditions
Jellyfish Warning
High water temps may attract jellyfish swarms.
Swim Index
⚠️ Mixed Conditions
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Puerto Rico
Flight Traffic
Busy
74/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~159
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Juan
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:05
☀️ Noon
12:31
🌇 Sunset
18:56
⏱️ Daylight
12h 50m
Wind Speed
21.5 km/h
Moderate wind
Sunshine
11.3 hrs
Direct Sun (Cloud-free)
Humidity
78%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for San Juan
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in San Juan
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🔴 Very Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Moderate seismic activity. Occasional tremors possible.
Atlantic Hurricane Risk
Season: Jun - Nov
"According to 30YearWeather's analysis of 30 years of NASA satellite data, San Juan on August 9 averages 31.2°C with a 34% precipitation probability. Wedding/Outdoor Event Score: 84/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
San Juan Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
August 10
31.3°C • 30% rain
Score
87
August 11
31.3°C • 29% rain
Score
87
August 12
31.4°C • 28% rain
Score
87
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
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📍 Is San Juan Worth Visiting on August 9?
Planning a trip to San Juan on August 9? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 31.2°C with a 34% historical precipitation risk.
✈️ Travel Logistics: Approximately 159 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Puerto Rico, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 29.5°C (hot soup). Wave conditions are generally fun waves with heights around 1.08m.
📊 Historical Extremes: The hottest August 9 recorded in the last 30 years saw temperatures hit 32.5°C in 2021, while the coldest dropped to 24°C in 2019.