March 18 is generally a great time to visit San Antonio. While there is a slight chance of rain (27%), showers are usually brief. Expect comfortable 24°C weather. As it's peak season for San Antonio, we recommend booking your stay well in advance to secure the best rates.
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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 March 18
"Mild & Comfortable. Expect average highs of 23.7°C. 27% chance of rain."
What to Wear in San Antonio in March
Based on historical data for March 18, San Antonio typically experiences temperatures between 12.9°C and 23.7°C. We recommend packing t-shirt, light clothing to stay comfortable. With a 27% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for San Antonio
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
23.7°C
Daytime Peak
Average Low
12.9°C
Nighttime Low
Feels Like
24.1°C
☀️ Feels accurate
Rain Chance
27%
Avg 1.9mm if it rains
Cloud Cover
53%
Overcast
Pressure
1016.6 hPa
Medium volatility
San Antonio Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
~ Expect variable conditions. Have flexible plans and pack for multiple weather scenarios.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
07:00 - 10:00
16:00 - 19:00
Type I-II
🔴 24 min to burn
Type III-IV
🟡 36 min to burn
Type V-VI
🟢 60 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
16.5°C
Noticeable
Heat Stress
Low
No heat warning
😊 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United States
Flight Traffic
High
80/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~130
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Antonio
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
07:41
☀️ Noon
13:43
🌇 Sunset
19:45
⏱️ Daylight
12h 3m
Wind Speed
19.7 km/h
Gentle breeze
Sunshine
7.9 hrs
Direct Sun (Cloud-free)
Humidity
64%
Slightly humid
Travel Intelligence
Exclusive flight analytics & health data for San Antonio
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
Add your home location in settings to see airport details.
Travel Health & Safety in San Antonio
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟢 Moderate
Price Level
💰💰 Moderate
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
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 March 18 averages 23.7°C with a 27% precipitation probability. Wedding/Outdoor Event Score: 94/100."
— 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
March 23
24.9°C • 15% rain
Score
100
March 22
24.1°C • 17% rain
Score
99
March 24
25.2°C • 16% rain
Score
99
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (March 18) in other destinations
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📍 Is San Antonio Worth Visiting on March 18?
Planning a trip to San Antonio on March 18? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 23.7°C with a 27% historical precipitation risk.
✈️ Travel Logistics: Approximately 130 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest March 18 recorded in the last 30 years saw temperatures hit 30.3°C in 2025, while the coldest dropped to 6.2°C in 2023.