Smoke: keep one room clean
Shut the windows and run an air purifier sized for the room.
Wildfire smoke guide →Air quality in Tennessee, county by county
23 Tennessee counties have enough EPA monitor data to count bad-air days. Weighted by population, they averaged about 3 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 Tennessee county, weighted by population, almost no smoky days (fine particles over 35.4 µg/m³, mostly wildfire smoke) and about 1 high-ozone day a year at its worst spot (2018 to 2022). See every county on the map.
Every Tennessee county with monitors
Most bad-air days first. 12 have a full report. Compare with the worst and the cleanest counties in the US.
| County | Bad-air days a year | |
|---|---|---|
| Shelby CountyMemphisOzone | 7.4 | |
| Davidson CountyOzone | 3.4 | |
| Sumner CountyHendersonvilleOzone | 3.0 | |
| Blount CountyMaryvilleOzone and particles | 2.4 | |
| Knox CountyKnoxvilleSummer smoke | 2.2 | |
| Hamilton CountyChattanoogaOzone | 2.0 | |
| Wilson CountyLebanonOzoneparticles not measured | 1.0 | |
| Williamson CountyFranklinOzoneparticles not measured | 0.8 | |
| Jefferson CountyOzoneparticles not measured | 0.6 | |
| Montgomery CountySmokeozone not measured | 0.6 | |
| Roane CountySmokeozone not measured | 0.6 | |
| Sevier CountySeviervilleOzoneparticles not measured | 0.6 | |
| Anderson CountyOak RidgeRarely badparticles not measured | 0.4 | |
| Claiborne CountyRarely badparticles not measured | 0.4 | |
| Dyer CountyDyersburgRarely badozone not measured | 0.4 | |
| Madison CountyJacksonRarely badozone not measured | 0.4 | |
| McMinn CountyAthensRarely badozone not measured | 0.4 | |
| Sullivan CountyKingsportRarely bad | 0.4 | |
| Loudon CountyLenoir CityRarely bad | 0.2 | |
| Maury CountyColumbiaRarely badozone not measured | 0.2 | |
| Putnam CountyCookevilleRarely badozone not measured | 0.2 | |
| DeKalb CountyRarely badparticles not measured | 0.0 | |
| Lawrence CountyLawrenceburgRarely badozone not measured | 0.0 | |
| No Tennessee 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 Tennessee
Which county in Tennessee has the worst air?
Among Tennessee counties with EPA monitors, Shelby County had the most bad-air days from 2021 to 2025: about 7 bad-air days a year with an AQI over 100. That's about 1 day in 49.
How often is the air bad in Tennessee?
Weighted by population, Tennessee counties with monitors averaged about 3 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.
Which county in Tennessee has the cleanest air?
2 of the 23 counties with enough monitor data had no bad-air days at all from 2021 to 2025, including Lawrence County and DeKalb County. Counties without monitors aren't ranked.
Where can I check today's air quality in Tennessee?
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.