# Counties in South Carolina by median Air Quality Index (US EPA), 2007

All 25 values come from U.S. Environmental Protection Agency for 2007, so the places are comparable. 3 counties have no value for that period and are not ranked.

- Indicator id: `aqi_median`
- Unit: index
- Definition: Median of the daily Air Quality Index (AQI) values of a US county over the days of the year with an AQI, from the EPA AirData annual summaries. The daily county AQI is the highest AQI among the monitors and pollutants reported that day (ozone, PM2.5, PM10, carbon monoxide and nitrogen dioxide). Lower is cleaner: 0 to 50 is good, 51 to 100 moderate and above 100 unhealthy for sensitive groups.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: median 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: median daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/median-air-quality-index/south-carolina-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Greenville County | 61 |
| 2 | Richland County | 60 |
| 3 | Spartanburg County | 59 |
| 4 | Greenwood County | 57 |
| 4 | Lexington County | 57 |
| 6 | Charleston County | 55 |
| 6 | Florence County | 55 |
| 8 | Horry County | 52 |
| 9 | Abbeville County | 51 |
| 9 | Pickens County | 51 |
| 11 | Beaufort County | 50 |
| 11 | Union County | 50 |
| 13 | Chester County | 48 |
| 14 | Chesterfield County | 47 |
| 14 | Darlington County | 47 |
| 14 | York County | 47 |
| 17 | Oconee County | 45 |
| 18 | Edgefield County | 44 |
| 18 | Williamsburg County | 44 |
| 20 | Aiken County | 42 |
| 21 | Colleton County | 41 |
| 22 | Barnwell County | 40 |
| 23 | Cherokee County | 39 |
| 24 | Berkeley County | 36 |
| 25 | Georgetown County | 26 |