May 20 is generally a great time to visit San Antonio. While there is a slight chance of rain (24%), showers are usually brief. Expect comfortable 31°C weather. San Antonio is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
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Essential Travel Info for San Antonio
Currency
USD
$ United States dollar
Language
English
Driving
Right side
Connect
As of Dec 2021, San Antonio has 5G from ...
Safety
Moderate Safety
GPI: 2.44
San Antonio Weather Forecast for May 20
"Warm & Sunny. Expect average highs of 31°C. 24% chance of rain."
What to Wear in San Antonio in May
Based on historical data for May 20, San Antonio typically experiences temperatures between 20.4°C and 31°C. We recommend packing t-shirt, light clothing to stay comfortable. Trends suggest it will stay mostly dry (24% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for San Antonio
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
31°C
Daytime Peak
Average Low
20.4°C
Nighttime Low
Feels Like
37.6°C
🔥 Heat index effect
Rain Chance
24%
Avg 1.2mm if it rains
Cloud Cover
53%
Overcast
Pressure
1012.3 hPa
Medium volatility
San Antonio Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 83% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30+ required, seek shade
06:00 - 10:00
16:00 - 20:00
Type I-II
🔴 13 min to burn
Type III-IV
🟡 20 min to burn
Type V-VI
🟢 33 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
24.9°C
Humid/Sticky
Heat Index
37.6°C
Feels hotter
😐 Best outdoor time:
Early morning (6-9 AM) or evening (after 6 PM)
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United States
Flight Traffic
High
97/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~158
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Antonio
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:40
☀️ Noon
13:31
🌇 Sunset
20:23
⏱️ Daylight
13h 43m
Wind Speed
19.3 km/h
Gentle breeze
Sunshine
10.4 hrs
Direct Sun (Cloud-free)
Humidity
70%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for San Antonio
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in San Antonio
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Mild discomfort possible for arthritic conditions.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Rare minor tremors. Buildings are earthquake-resistant.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, San Antonio on May 20 averages 31°C with a 24% precipitation probability. Wedding/Outdoor Event Score: 89/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
San Antonio Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
May 13
30°C • 24% rain
Score
91
May 14
30.2°C • 24% rain
Score
91
May 15
30.4°C • 26% rain
Score
90
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (May 20) in other destinations
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📍 Is San Antonio Worth Visiting on May 20?
Planning a trip to San Antonio on May 20? 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°C with a 24% historical precipitation risk.
✈️ Travel Logistics: Approximately 158 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest May 20 recorded in the last 30 years saw temperatures hit 37.5°C in 2022, while the coldest dropped to 15.1°C in 2021.