# Counties in West Virginia by share of days with good air quality (US EPA AQI), 2005

All 18 values come from U.S. Environmental Protection Agency for 2005, so the places are comparable. 2 counties have no value for that period and are not ranked.

- Indicator id: `aqi_good_days_share`
- Unit: %
- Definition: Days with a daily Air Quality Index of 0 to 50 (good) as a percentage of the days of the year with an AQI in a US county. Calculated by Invokely from the day counts in the EPA AirData annual summaries; both counts are stored with each value.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts (https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual)
- Retrieved: 2026-10-12
- Citation: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/good-air-quality-days-share/west-virginia-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Gilmer County | 91.1 |
| 2 | Wayne County | 86.8 |
| 3 | Greenbrier County | 75.1 |
| 4 | Tucker County | 74.7 |
| 5 | Brooke County | 67.4 |
| 6 | Hancock County | 61.1 |
| 7 | Kanawha County | 53.8 |
| 8 | Monongalia County | 47.1 |
| 9 | Summers County | 46.4 |
| 10 | Berkeley County | 46.2 |
| 11 | Wood County | 45.4 |
| 12 | Cabell County | 39.8 |
| 13 | Ohio County | 38.6 |
| 14 | Raleigh County | 35.9 |
| 15 | Mercer County | 30.2 |
| 16 | Harrison County | 23.5 |
| 17 | Marion County | 18.6 |
| 18 | Marshall County | 15.7 |