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Air quality in Virginia

EPA monitors report from 32 of Virginia’s 133 counties. That is the honest limit of this page: the other 101 are not measured, not clean. In 2025 the most affected monitored county was Arlington County, with 2 days above the moderate category.

32
Counties with monitors
101
Counties without
7
Days above moderate, 2025
Summed across monitored counties
10.4%
Adults with asthma
Population-weighted county estimate

County by county

Monitored Virginia counties

GoodModerateUnhealthy for sensitive groupsUnhealthyVery unhealthyHazardous

EPA Air Quality System annual summaries by county, 2025. The 90th percentile AQI describes a day worse than nine out of ten, which is a steadier measure than the annual maximum a single wildfire can set.

Not measured

101 counties without a monitor

No EPA monitor reported from these counties, so there is no air quality record to publish. Their radon zone is known, and radon is measured in the building rather than the air outside it.

Other states

Air quality elsewhere