# Counties in Kansas by share of days unhealthy for sensitive groups or worse (US EPA AQI), 2009

All 15 values come from U.S. Environmental Protection Agency for 2009, so the places are comparable. 8 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/kansas-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Sedgwick County | 1.6 |
| 2 | Sumner County | 1.1 |
| 3 | Brown County | 0.9 |
| 4 | Wyandotte County | 0.5 |
| 5 | Johnson County | 0.3 |
| 5 | Linn County | 0.3 |
| 5 | Shawnee County | 0.3 |
| 5 | Trego County | 0.3 |
| 9 | Chase County | 0 |
| 9 | Ford County | 0 |
| 9 | Leavenworth County | 0 |
| 9 | Montgomery County | 0 |
| 9 | Neosho County | 0 |
| 9 | Riley County | 0 |
| 9 | Sherman County | 0 |