# Counties in Tennessee by share of days unhealthy for sensitive groups or worse (US EPA AQI), 2003

All 30 values come from U.S. Environmental Protection Agency for 2003, so the places are comparable. 12 counties have no value for that period and are not ranked.

- Indicator id: `aqi_unhealthy_sensitive_or_worse_days_share`
- Unit: %
- Definition: Days with a daily Air Quality Index above 100 (unhealthy for sensitive groups, unhealthy, very unhealthy or hazardous) 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; the counts are stored with each value.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: days with an AQI above 100 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: days with an AQI above 100 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/unhealthy-air-quality-days-share/tennessee-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Blount County | 11.5 |
| 2 | Shelby County | 9.9 |
| 3 | Sevier County | 9.1 |
| 4 | Sumner County | 8.4 |
| 5 | Williamson County | 8.2 |
| 6 | Wilson County | 7.4 |
| 7 | Rutherford County | 7.2 |
| 8 | Hamilton County | 7 |
| 9 | Meigs County | 6.9 |
| 10 | Putnam County | 6.8 |
| 11 | Knox County | 5.8 |
| 12 | Jefferson County | 5.7 |
| 13 | Obion County | 5.3 |
| 14 | Sullivan County | 5.2 |
| 15 | Humphreys County | 4.4 |
| 16 | Haywood County | 4.3 |
| 17 | Anderson County | 4.2 |
| 18 | Davidson County | 4.1 |
| 19 | Lawrence County | 3.2 |
| 20 | DeKalb County | 2 |
| 21 | Montgomery County | 1.6 |
| 22 | Claiborne County | 1.4 |
| 23 | Dyer County | 1 |
| 24 | McMinn County | 0.6 |
| 25 | Union County | 0.3 |
| 26 | Bradley County | 0 |
| 26 | Loudon County | 0 |
| 26 | Madison County | 0 |
| 26 | Maury County | 0 |
| 26 | Roane County | 0 |