Smoke: keep one room clean
Shut the windows and run an air purifier sized for the room.
Wildfire smoke guide →Air quality in West Virginia, county by county
11 West Virginia counties have enough EPA monitor data to count bad-air days. Weighted by population, they averaged about 1 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 West Virginia county, weighted by population, almost no smoky days (fine particles over 35.4 µg/m³, mostly wildfire smoke) and almost no high-ozone days a year at its worst spot (2018 to 2022). See every county on the map.
Every West Virginia county with monitors
Most bad-air days first. 8 have a full report. Compare with the worst and the cleanest counties in the US.
| County | Bad-air days a year | |
|---|---|---|
| Hancock CountyWeirtonOzone | 1.4 | |
| Berkeley CountyMartinsburgOzone and particles | 1.0 | |
| Wood CountyParkersburgOzone | 1.0 | |
| Marshall CountySmokeozone not measured | 0.8 | |
| Ohio CountyWheelingOzone | 0.8 | |
| Brooke CountySmokeozone not measured | 0.6 | |
| Monongalia CountyMorgantownRarely bad | 0.4 | |
| Cabell CountyHuntingtonRarely bad | 0.2 | |
| Kanawha CountyCharlestonRarely bad | 0.2 | |
| Greenbrier CountyRarely badparticles not measured | 0.0 | |
| Tucker CountyRarely bad | 0.0 | |
| No West Virginia 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 West Virginia
Which county in West Virginia has the worst air?
No West Virginia county with a monitor averaged more than about 1 bad-air day a year from 2021 to 2025. Hancock County was highest, at 1.4 a year.
How often is the air bad in West Virginia?
Weighted by population, West Virginia counties with monitors averaged about 1 bad-air day 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 West Virginia has the cleanest air?
2 of the 11 counties with enough monitor data had no bad-air days at all from 2021 to 2025, including Greenbrier County and Tucker County. Counties without monitors aren't ranked.
Where can I check today's air quality in West Virginia?
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.