# Counties in Oregon by highest daily Air Quality Index (US EPA), 2022

All 23 values come from U.S. Environmental Protection Agency for 2022, so the places are comparable. 3 counties have no value for that period and are not ranked.

- Indicator id: `aqi_max`
- Unit: index
- Definition: Highest daily Air Quality Index (AQI) value recorded in a US county during the year, from the EPA AirData annual summaries. Values above 500 are beyond the AQI scale and are published as EPA computes them.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: highest daily AQI (https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual)
- Publisher page: https://invokely.ai/en/publishers/environmental-protection-agency
- Retrieved: 2026-10-12
- Citation: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/highest-daily-air-quality-index/oregon-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Lane County | 520 |
| 2 | Josephine County | 252 |
| 3 | Deschutes County | 205 |
| 4 | Wallowa County | 195 |
| 5 | Clackamas County | 168 |
| 5 | Marion County | 168 |
| 7 | Jackson County | 165 |
| 7 | Multnomah County | 165 |
| 9 | Washington County | 164 |
| 10 | Klamath County | 163 |
| 11 | Columbia County | 162 |
| 12 | Umatilla County | 141 |
| 13 | Union County | 130 |
| 14 | Lake County | 129 |
| 15 | Crook County | 128 |
| 16 | Linn County | 127 |
| 17 | Baker County | 124 |
| 18 | Harney County | 114 |
| 19 | Grant County | 108 |
| 19 | Jefferson County | 108 |
| 21 | Douglas County | 69 |
| 22 | Benton County | 68 |
| 23 | Wasco County | 50 |