# Counties in Virginia by median Air Quality Index (US EPA), 1999

All 42 values come from U.S. Environmental Protection Agency for 1999, so the places are comparable. 18 counties have no value for that period and are not ranked.

- Indicator id: `aqi_median`
- Unit: index
- Definition: Median of the daily Air Quality Index (AQI) values of a US county over the days of the year with an AQI, from the EPA AirData annual summaries. The daily county AQI is the highest AQI among the monitors and pollutants reported that day (ozone, PM2.5, PM10, carbon monoxide and nitrogen dioxide). Lower is cleaner: 0 to 50 is good, 51 to 100 moderate and above 100 unhealthy for sensitive groups.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: median daily AQI (https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual)
- Publisher page: https://invokely.ai/en/publishers/environmental-protection-agency
- Retrieved: 2026-10-12
- Citation: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: median daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/median-air-quality-index/virginia-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Wythe County | 71 |
| 2 | Bristol city | 62 |
| 3 | Rockbridge County | 61 |
| 4 | Lynchburg city | 59 |
| 5 | Salem city | 58 |
| 6 | Virginia Beach city | 57 |
| 7 | Chesapeake city | 56 |
| 7 | Fairfax County | 56 |
| 7 | Richmond city | 56 |
| 10 | Henrico County | 54 |
| 10 | Stafford County | 54 |
| 12 | Page County | 52 |
| 13 | Fauquier County | 51 |
| 13 | Madison County | 51 |
| 13 | Suffolk city | 51 |
| 16 | Chesterfield County | 50 |
| 16 | Frederick County | 50 |
| 16 | Hanover County | 50 |
| 19 | Giles County | 49 |
| 20 | Arlington County | 48 |
| 21 | Hampton city | 44 |
| 21 | Loudoun County | 44 |
| 23 | Alexandria city | 43 |
| 23 | Charles City County | 43 |
| 25 | Prince Edward County | 42 |
| 26 | Prince William County | 37 |
| 27 | Caroline County | 35 |
| 28 | Norfolk city | 34 |
| 28 | Roanoke County | 34 |
| 30 | Rockingham County | 21 |
| 31 | Winchester city | 19 |
| 31 | Wise County | 19 |
| 33 | Warren County | 18 |
| 34 | Carroll County | 17 |
| 34 | Charlottesville city | 17 |
| 36 | Culpeper County | 16 |
| 36 | Fredericksburg city | 16 |
| 36 | Newport News city | 16 |
| 39 | Roanoke city | 15 |
| 40 | King William County | 14 |
| 41 | Tazewell County | 13 |
| 42 | Northumberland County | 12 |