# Counties in Oklahoma by share of days with good air quality (US EPA AQI), 2018

All 25 values come from U.S. Environmental Protection Agency for 2018, so the places are comparable. 20 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/oklahoma-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Custer County | 97.5 |
| 2 | Choctaw County | 93.4 |
| 3 | Muskogee County | 90.8 |
| 4 | Le Flore County | 88.2 |
| 5 | Creek County | 88.1 |
| 6 | Mayes County | 87.4 |
| 7 | Bryan County | 85.4 |
| 8 | Osage County | 84.4 |
| 9 | Canadian County | 83.3 |
| 10 | McClain County | 82.2 |
| 11 | Love County | 75.4 |
| 12 | Jefferson County | 74.2 |
| 13 | Adair County | 72.1 |
| 14 | Sequoyah County | 71.3 |
| 15 | Comanche County | 65.8 |
| 16 | Pittsburg County | 63.9 |
| 17 | Carter County | 63.8 |
| 18 | Dewey County | 58.6 |
| 19 | Nowata County | 52.5 |
| 20 | Washington County | 50 |
| 21 | Kay County | 49.6 |
| 22 | Oklahoma County | 43.8 |
| 23 | Cleveland County | 43.6 |
| 24 | Ottawa County | 42.7 |
| 25 | Tulsa County | 32.1 |