# Counties in Virginia by highest daily 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_max`
- Unit: index
- Definition: Highest daily Air Quality Index (AQI) value recorded in a US county during the year, from the EPA AirData annual summaries. Values above 500 are beyond the AQI scale and are published as EPA computes them.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: highest 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: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/highest-daily-air-quality-index/virginia-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Charles City County | 223 |
| 2 | Fairfax County | 210 |
| 3 | Stafford County | 207 |
| 4 | Suffolk city | 206 |
| 5 | Hanover County | 204 |
| 6 | Hampton city | 203 |
| 7 | Henrico County | 202 |
| 8 | Loudoun County | 201 |
| 9 | Arlington County | 200 |
| 10 | Caroline County | 195 |
| 11 | Alexandria city | 192 |
| 12 | Madison County | 190 |
| 13 | Chesterfield County | 185 |
| 13 | Roanoke County | 185 |
| 15 | Rockbridge County | 182 |
| 16 | Page County | 177 |
| 16 | Prince William County | 177 |
| 18 | Fauquier County | 174 |
| 19 | Giles County | 172 |
| 20 | Frederick County | 169 |
| 21 | Wythe County | 166 |
| 22 | Prince Edward County | 156 |
| 23 | Richmond city | 133 |
| 24 | Bristol city | 122 |
| 25 | Chesapeake city | 120 |
| 26 | Norfolk city | 117 |
| 27 | Newport News city | 116 |
| 28 | Virginia Beach city | 113 |
| 29 | Lynchburg city | 111 |
| 30 | Salem city | 97 |
| 31 | Roanoke city | 96 |
| 32 | Northumberland County | 49 |
| 33 | Charlottesville city | 47 |
| 34 | King William County | 45 |
| 34 | Rockingham County | 45 |
| 34 | Winchester city | 45 |
| 37 | Warren County | 41 |
| 38 | Carroll County | 37 |
| 38 | Culpeper County | 37 |
| 40 | Fredericksburg city | 36 |
| 40 | Wise County | 36 |
| 42 | Tazewell County | 33 |