What Is the Air Quality in Greenville, South Carolina?

Greenville, South Carolina earns a C — air quality is fair, but not great. With a 5-year median AQI of 49, the city sees a meaningful number of "Moderate" days each year, when the EPA flags air as a concern for unusually sensitive people.

Greenville, South Carolina's 5-year median AQI of 49 is 8 points above the national average of 41 — meaningfully more polluted than the typical U.S. metro tracked here. Within South Carolina, Greenville, South Carolina runs more polluted than the state average of 39 — local sources or geography are concentrating pollution above the state's typical reading.

For context within South Carolina: Colleton, South Carolina currently holds the state's cleanest grade (A, AQI 26), while York, South Carolina sits at the bottom (C, AQI 44).

Air quality in Greenville, South Carolina has held roughly steady over the past decade, with year-to-year shifts in median AQI of less than half a point. That stability makes the city's long-run grade a reliable signal of what residents can expect day-to-day.

In 2014, Greenville, South Carolina posted a median AQI of 49. By 2023 that figure was 52 — a rise of 3 AQI points dirtier across 10 years of EPA records.

Across the past five years, this area has logged just 4 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 1 days per year, or roughly one every other month. That is a low count by national standards.

Healthy adults can continue normal outdoor activity in most weather, but should pay attention to AQI alerts during the worst pollution windows. People with asthma, heart disease, or pregnancy should reduce prolonged or intense outdoor exertion on flagged days, and consider running an indoor HEPA air cleaner during peak season. Because PM2.5 penetrates deep into the lungs and bloodstream, an N95 or KN95 mask provides meaningful protection on smoky or high-particulate days — surgical masks do not.