# Counties in Louisiana by highest daily Air Quality Index (US EPA), 2005

All 28 values come from U.S. Environmental Protection Agency for 2005, so the places are comparable. 2 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/louisiana-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Pointe Coupee Parish | 201 |
| 2 | Iberville Parish | 200 |
| 3 | East Baton Rouge Parish | 192 |
| 4 | West Baton Rouge Parish | 179 |
| 5 | Ascension Parish | 169 |
| 6 | Calcasieu Parish | 164 |
| 7 | Bossier Parish | 161 |
| 8 | Lafayette Parish | 159 |
| 8 | St. Bernard Parish | 159 |
| 10 | Livingston Parish | 156 |
| 10 | St. James Parish | 156 |
| 12 | Caddo Parish | 154 |
| 12 | Jefferson Parish | 154 |
| 12 | Lafourche Parish | 154 |
| 12 | Ouachita Parish | 154 |
| 16 | St. John the Baptist Parish | 151 |
| 17 | Orleans Parish | 136 |
| 17 | St. Charles Parish | 136 |
| 17 | St. Mary Parish | 136 |
| 20 | Beauregard Parish | 122 |
| 21 | Grant Parish | 119 |
| 21 | Tangipahoa Parish | 119 |
| 23 | Winn Parish | 99 |
| 24 | Concordia Parish | 95 |
| 24 | Rapides Parish | 95 |
| 26 | Terrebonne Parish | 93 |
| 27 | St. Tammany Parish | 92 |
| 28 | Plaquemines Parish | 87 |