The orange afternoon usually shows up before the warning does. On a hot San Antonio day, ground-level ozone over Bexar County can push the air quality map from yellow to orange while the sky still looks clear, and most people don’t check until someone in the house starts coughing. A live AQI map closes that gap. It tells you what your own ZIP is breathing before you send the kids outside or lace up for a run.
We ship filters across the metro every week, and the households that handle these days well all start the same way. They read the local number instead of the citywide headline, then they match it to a filter that fits. This page covers both halves: where to read today’s air quality, and what to do for your indoor air when it climbs.
TL;DR Quick Answers
Live Air Quality Index AQI Map Now Today In San Antonio, TX
Check San Antonio’s live AQI by ZIP on the EPA AirNow interactive map, which pulls current readings from Bexar County’s regulatory monitors. The citywide number often reads cleaner than your own block, so trust the monitor closest to you and refresh it in the afternoon, when ozone tends to peak.
- Where to look: EPA AirNow shows the current AQI by monitor and ZIP across the San Antonio area. Most weather apps pull from that same federal feed.
- What’s safe: 0–50 is good and 51–100 is moderate. Once it passes 100, sensitive groups should ease off outdoor effort.
- Today’s likely driver: ozone on hot afternoons from spring through fall, wildfire smoke as PM2.5 on south winds, or mountain cedar from December through February.
- What you control: a clean, correctly sized filter does more for your indoor air on a high-AQI day than any forecast.
Top Takeaways
- Start with the live map. Almost every air quality app draws from the federal AirNow feed, so a San Antonio AQI map today puts you on the same source the agencies use.
- The citywide AQI hides your block. The same afternoon can read moderate on one side of town and unhealthy on the other.
- Ozone is the warm-season problem. Hot, sunny afternoons from spring through fall cook traffic emissions into ground-level ozone.
- Smoke and cedar are the off-season problems. Wildfire smoke rides in on south winds as PM2.5, and mountain cedar drives the December-through-February allergy spike.
- Indoor air is the part you control. When the number climbs, a fresh, correctly sized filter does more for your home than any forecast.
Table of Contents
How Bad Is San Antonio Air Right Now? Reading Today’s AQI
The Air Quality Index runs from 0 to 500 across six color bands. Zero to 50 reads green and means the air is good. Yellow covers 51 to 100, the moderate range most people barely notice. Orange starts at 101 and tells sensitive groups to take it easy, and red, purple, and maroon mark the harder days above that. EPA AirNow builds the live number from regulatory monitors, so refresh it in the afternoon, when ozone tends to peak.
Bexar County Air Quality by ZIP and Neighborhood
Three regulatory monitors feed the federal map for the San Antonio area: San Antonio Northwest (C23), Camp Bullis (C58), and Calaveras Lake (C59). From the orders we ship across the metro, we’ve learned the citywide average can paper over real gaps from one ZIP to the next. Find the monitor closest to your home and trust that reading over the metro-wide figure. The air a few miles away is not the air at your door.
What Drives San Antonio’s Air: Ozone, Smoke, and Cedar
Ground-level ozone climbs on hot, sunny afternoons from spring through fall, when sunlight reacts with traffic exhaust. Bexar County does not meet the federal 2015 ground-level ozone standard, so high-ozone days follow a summer pattern rather than catch anyone off guard. Wildfire smoke is the wildcard. During dry stretches, south winds carry PM2.5 into the county, and it usually shows up as the dominant pollutant on the map. Winter then brings mountain cedar from December through February, along with the cedar fever a lot of residents already know too well.
PM2.5 and Ozone: What the Numbers Mean for Your Health
Sensitive groups feel it first. Children, older adults, and anyone with asthma or a heart condition should scale back outdoor effort once the AQI passes 100. PM2.5 is the fine particle the body cannot filter on its own, which is what makes smoke days worth extra care. On orange and red afternoons, move the workout indoors and keep the windows shut.
Protecting Your Indoor Air When San Antonio’s AQI Climbs
Your filter is the one variable you fully control. For smoke and ozone days, MERV 11 to MERV 13 captures fine particles well. Here is the part we would rather you hear from us than learn the hard way: a fresh MERV 8 outperforms a clogged MERV 13, and MERV 13 can choke airflow on a system that was not sized for it, so confirm your static pressure before going higher. Change filters more often when smoke settles in. If you run a MERV 13, here is how often to change a MERV 13 filter. Measure the slot rather than the old filter, and if your size turns out to be one of the uncommon ones, that is the part we handle.
“The citywide AQI tells you about the city, not your street. Read the monitor nearest your ZIP, pair it with a filter that fits, and you have handled the half of clean air that is actually in your hands.”
Essential Resources We Recommend to Every San Antonio Reader
Read the Live Federal Number: EPA AirNow AQI Basics
Start here when you want to know what the color on the map means for your afternoon. AirNow AQI Basics from the EPA
See What Is Coming: TCEQ Texas Air Quality Forecast
Our San Antonio customers use this to plan around Ozone Action Days before they arrive. TCEQ Texas air quality forecast
Check Your County Status: Bexar County Air Quality Division
Local context on monitoring, alerts, and the county’s ozone status. Bexar County Air Quality Division
Track Regional Monitoring: Alamo Area MPO Air Quality and Conformity
Where the regulatory monitors sit and how the region tracks ozone over time. Alamo Area MPO air quality and conformity
Get Local Alerts: National Weather Service Austin and San Antonio Air Quality
Relays the air quality alerts that TCEQ issues for the metro. National Weather Service Austin and San Antonio air quality
Understand the Main Pollutant: EPA Ground-Level Ozone Basics
Why hot afternoons turn traffic emissions into the smog that drives summer readings. EPA ground-level ozone basics
Plan for Cedar Season: AAFA Tree Pollen Allergy Guide
From December through February, mountain cedar drives the indoor-air calls we get. AAFA tree pollen allergy guide
Statistics Worth Knowing
The American Lung Association ranks the San Antonio metro 28th worst in the nation for ozone pollution in its 2026 State of the Air report. American Lung Association State of the Air ozone findings
The CDC notes that fine particles, known as PM2.5, are small enough to reach the deep parts of the lungs and even enter the bloodstream. CDC air quality and pollutants guide
The U.S. Department of Energy notes that dirty, clogged filters reduce airflow and system efficiency, which raises energy use. DOE Energy Saver air conditioner maintenance
Final Thoughts and Opinion
The citywide AQI makes a fine headline and a poor instruction. What changes your day is the reading from the monitor nearest your ZIP, paired with a filter that fits your system. Across the orders we ship into Bexar County, the households that ride out high-AQI days best are not the ones running the highest MERV rating. They are the ones who check the local number and change a correctly sized filter on schedule.
Frequently Asked Questions
How Bad Is the Air in San Antonio Right Now?
Check the live AQI for your ZIP on the EPA AirNow map, since the number shifts through the day. Afternoon readings during ozone season tend to run the highest.
Where Can I See a Live San Antonio AQI Map?
The EPA AirNow interactive map shows current readings by monitor across Bexar County. Most weather apps pull from that same federal feed.
What Is a Safe AQI Level for San Antonio?
Zero to 50 is good and 51 to 100 is moderate for most people. Once it passes 100, sensitive groups should ease up outdoors.
Why Does San Antonio Air Quality Differ by Neighborhood?
The citywide average smooths over local differences in traffic, wind, and elevation. The monitor closest to your ZIP gives you a truer read than the metro number.
When Is Ozone Worst in San Antonio?
Ground-level ozone peaks on hot, sunny afternoons from spring through fall. Bexar County has a long record of summer ozone exceedances.
Does Wildfire Smoke Reach San Antonio?
Yes. During dry stretches, south winds can carry PM2.5 from regional fires into Bexar County, where it usually becomes the dominant pollutant on the map.
What Is PM2.5 and Why Does It Matter in Bexar County?
PM2.5 is fine particulate matter small enough to reach deep into the lungs. It is the pollutant to watch on smoke days, not just ozone days.
Is Bexar County in Ozone Nonattainment?
Yes. The county does not meet the federal 2015 ground-level ozone standard, which is why local ozone forecasts get so much attention.
What MERV Rating Helps With San Antonio Smoke and Ozone Days?
MERV 11 to MERV 13 captures fine particles well, as long as your system can handle it. A fresh MERV 8 still beats a clogged MERV 13.
How Often Should I Change My Filter During High-AQI Periods?
Check it monthly through heavy smoke or ozone stretches and change it sooner than usual. A loaded filter restricts airflow and stops doing its job.
Ready to Take Control of Your Indoor Air on San Antonio’s High-AQI Days?
Now that you can read today’s Bexar County AQI and match it to the right filter, the fit is the easy part. Shop FilterFlowAC.com for your exact size, including the uncommon dimensions other retailers skip.