# Counties in Kentucky by share of days with good air quality (US EPA AQI), 2004

All 36 values come from U.S. Environmental Protection Agency for 2004, so the places are comparable. 19 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/kentucky-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Harlan County | 100 |
| 1 | Marshall County | 100 |
| 3 | Scott County | 94.6 |
| 4 | Morgan County | 86 |
| 5 | Graves County | 85.3 |
| 6 | Boone County | 84.9 |
| 7 | Washington County | 83.7 |
| 8 | Hancock County | 82 |
| 9 | Jessamine County | 81.8 |
| 10 | Pulaski County | 80.4 |
| 11 | McLean County | 75.9 |
| 12 | Greenup County | 75.5 |
| 13 | Simpson County | 74.7 |
| 14 | Livingston County | 74.6 |
| 15 | Oldham County | 71.7 |
| 16 | Carter County | 70.3 |
| 17 | Bullitt County | 70 |
| 18 | Pike County | 69.4 |
| 19 | Bell County | 69.2 |
| 20 | Daviess County | 68.9 |
| 21 | Trigg County | 68.8 |
| 22 | Henderson County | 68.7 |
| 23 | Fayette County | 66.4 |
| 24 | McCracken County | 66.1 |
| 25 | Edmonson County | 65.5 |
| 25 | Perry County | 65.5 |
| 27 | Warren County | 65 |
| 28 | Campbell County | 64.9 |
| 29 | Boyd County | 64 |
| 30 | Hardin County | 61.4 |
| 31 | Kenton County | 53.8 |
| 32 | Christian County | 52.5 |
| 33 | Madison County | 35.8 |
| 34 | Franklin County | 34.8 |
| 35 | Laurel County | 23.1 |
| 36 | Jefferson County | 18.9 |