Smoke: keep one room clean
Shut the windows and run an air purifier sized for the room.
Wildfire smoke guide →Air quality in Texas, county by county
44 Texas counties have enough EPA monitor data to count bad-air days. Weighted by population, they averaged about 18 days a year from 2021 to 2025 when the air was unhealthy for sensitive groups or worse.
CDC's model, which estimates every county from monitors and satellites, gives the average Texas county, weighted by population, about 1 smoky day (fine particles over 35.4 µg/m³, mostly wildfire smoke) and about 6 high-ozone days a year at its worst spot (2018 to 2022). See every county on the map.
Every Texas county with monitors
Most bad-air days first. 34 have a full report. Compare with the worst and the cleanest counties in the US.
| County | Bad-air days a year | |
|---|---|---|
| Harris CountyHoustonOzone | 37.0 | |
| El Paso CountyEl PasoOzone and particles | 36.8 | |
| Tarrant CountyFort WorthOzone | 24.6 | |
| Denton CountyDentonOzone | 24.0 | |
| Dallas CountyDallasOzone | 16.8 | |
| Cameron CountyBrownsvilleSummer smoke | 15.6 | |
| Bexar CountySan AntonioOzone | 14.0 | |
| Collin CountyPlanoOzoneparticles not measured | 14.0 | |
| Brazoria CountyPearlandOzone | 10.2 | |
| Galveston CountyLeague CityOzone | 9.4 | |
| Montgomery CountyConroeOzone | 9.4 | |
| Johnson CountyBurlesonOzoneparticles not measured | 7.8 | |
| Parker CountyWeatherfordOzoneparticles not measured | 7.4 | |
| Hidalgo CountyMcAllenSummer smoke | 6.6 | |
| Hood CountyGranburyOzoneparticles not measured | 6.6 | |
| Travis CountyAustinOzone | 6.4 | |
| Nueces CountySummer smoke | 6.0 | |
| Jefferson CountyBeaumontOzone | 5.6 | |
| Webb CountySummer smoke | 5.4 | |
| Kaufman CountyForneyOzone | 4.4 | |
| Bell CountyKilleenOzone | 4.2 | |
| McLennan CountyWacoOzone | 3.2 | |
| Harrison CountyMarshallSummer smoke | 2.6 | |
| Kleberg CountySmokeozone not measured | 2.2 | |
| Smith CountyTylerOzoneparticles not measured | 2.2 | |
| Atascosa CountyPleasantonSmokeozone not measured | 2.0 | |
| Navarro CountyCorsicanaOzone | 2.0 | |
| Randall CountyAmarilloOzoneparticles not measured | 2.0 | |
| Gregg CountyLongviewOzoneparticles not measured | 1.2 | |
| Orange CountyOrangeOzone | 1.2 | |
| Brewster CountyOzone | 1.0 | |
| Hunt CountyGreenvilleOzoneparticles not measured | 1.0 | |
| Lubbock CountySmokeozone not measured | 1.0 | |
| Ellis CountyWaxahachieOzone | 0.8 | |
| Potter CountyWinter particlesozone not measured | 0.8 | |
| Rockwall CountyRockwallOzoneparticles not measured | 0.8 | |
| Bowie CountyTexarkanaSmokeozone not measured | 0.6 | |
| Ector CountyOdessaRarely badozone not measured | 0.4 | |
| Maverick CountyEagle PassRarely badozone not measured | 0.4 | |
| Victoria CountyVictoriaRarely badparticles not measured | 0.4 | |
| Brazos CountyCollege StationRarely badozone not measured | 0.2 | |
| Polk CountyRarely badparticles not measured | 0.2 | |
| Karnes CountyRarely bad | 0.0 | |
| Wilson CountyRarely bad | 0.0 | |
| No Texas county with a monitor matches “”. Counties without a monitor aren't listed; a neighbor's numbers are a fair guide, or find it on the map. | ||
Counties without a monitor aren't listed. Air doesn't stop at the county line, so a neighbor's numbers are a fair guide.
What helps on a bad-air day
Check AirNow for today's reading and tomorrow's forecast, then match the step to the pollutant.
Upgrade the furnace filter
MERV 13 catches far more smoke than thin fiberglass filters.
Furnace filters →Questions people ask about air quality in Texas
Which county in Texas has the worst air?
Among Texas counties with EPA monitors, Harris County had the most bad-air days from 2021 to 2025: about 37 bad-air days a year with an AQI over 100. That's about 1 day in 10.
How often is the air bad in Texas?
Weighted by population, Texas counties with monitors averaged about 18 bad-air days a year from 2021 to 2025 with an AQI over 100, when children, older adults and people with asthma should cut back outdoors. That's about 1 day in 20.
Which county in Texas has the cleanest air?
2 of the 44 counties with enough monitor data had no bad-air days at all from 2021 to 2025, including Wilson County and Karnes County. Counties without monitors aren't ranked.
Where can I check today's air quality in Texas?
AirNow, run by the EPA and its partners, shows current readings and forecasts by ZIP code, and its fire and smoke map adds smoke plumes and low-cost sensors.
Sources: EPA AirData county AQI summaries, 2021 to 2025; CDC Environmental Public Health Tracking Network modeled PM2.5 and ozone, 2018 to 2022. Updated November 8, 2026.