Weather: San Juan — September
It's a rainy period, but great for indoor activities, museums, and lower prices.
☔ Climate Overview
September is a wet time to visit San Juan. Hot conditions with temperatures reaching 31°C—stay hydrated and seek shade. This is one of the wettest months—waterproof gear is essential. Being off-peak, you'll find better deals and fewer crowds. Sea temperature of 30°C is perfect for swimming.
Based on weather comfort, crowds, prices, and activity options
31°C
27°C
22days
12.3h
Feels like 37°C / 32°C — humidity makes it feel warmer
145mm
10.6h/day
82%
Very Muggy8.5
Very High16 km/h (gusts 32)
30°C 🏊 Comfortable
Is September a good time to visit San Juan?
It's a rainy period, but great for indoor activities, museums, and lower prices.
Now
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Air Quality
Travel Context
- CrowdsVery Quiet
- Travel Costs Value Rates
Daylight
06:13
18:29
Visiting San Juan in September: Pros & Cons
Pros
- Abundant sunshine for beach and outdoor fun
- Fewer crowds and better hotel deals
- Warm sea perfect for swimming and snorkeling
Cons
- Frequent rain may disrupt outdoor activities
- High humidity makes the heat feel oppressive
- Very high UV — sunscreen and shade essential
Things to Do in September
Recommended for This Weather
San Juan Weather by Month
| Month | Avg High | Avg Low | Rain | Sunshine | Humidity | UV Index | Crowds | Condition |
|---|---|---|---|---|---|---|---|---|
| Jan | 28°C | 24°C | 11d (40mm) | 10.3h | 79% Humid | 6.6 High | | Excellent |
| Feb | 28°C | 23°C | 11d (48mm) | 10.6h | 78% Humid | 7.5 Very High | | Excellent |
| Mar | 28°C | 23°C | 11d (35mm) | 11h | 77% Humid | 8.7 Very High | | Excellent |
| Apr | 29°C | 24°C | 13d (81mm) | 11.4h | 78% Muggy | 9.2 Very High | | Excellent |
| May | 30°C | 25°C | 12d (79mm) | 11.5h | 79% Muggy | 9.4 Very High | | Good |
| Jun | 31°C | 26°C | 12d (58mm) | 12h | 78% Muggy | 9.5 Very High | | Good |
| Jul | 31°C | 26°C | 15d (67mm) | 11.7h | 80% Very Muggy | 9.3 Very High | | Wet |
| Aug | 31°C | 27°C | 16d (88mm) | 11.1h | 80% Very Muggy | 9.1 Very High | | Wet |
| Sep Current | 31°C | 27°C | 22d (145mm) | 10.6h | 82% Very Muggy | 8.5 Very High | | Wet |
| Oct | 31°C | 26°C | 20d (131mm) | 9.9h | 82% Very Muggy | 7.4 Very High | | Wet |
| Nov | 29°C | 25°C | 17d (94mm) | 9.7h | 82% Very Muggy | 6.5 High | | Wet |
| Dec | 28°C | 24°C | 11d (42mm) | 10.1h | 80% Very Humid | 6.4 High | | Excellent |
San Juan
Caribbean capital with 500-year-old colonial Old San Juan, historic Spanish forts, vibrant beaches like Condado and Isla Verde, El Yunque rainforest, bioluminescent bays, and rich Puerto Rican culture blending Spanish, African, and Taíno influences.
View Full Destination Guide
What to Pack for September
Light, breathable fabrics like cotton and linen are essential. Opt for loose-fitting clothing in light colors to stay cool. A waterproof jacket and shoes are non-negotiable — showers are frequent. Don't forget a wide-brimmed hat and high-SPF sunscreen — the sun is strong.
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Frequently Asked Questions
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More San Juan Guides
Best Time to Visit
Coming soon
Things to Do
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Where to Stay
Best neighborhoods and hotel recommendations
Cost & Budget
Daily costs, money-saving tips, and budget breakdown
Itineraries
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Overview
Complete travel guide for San Juan: top things to do, itineraries, and typical costs.