Charleston, South Carolina Air Quality
Charleston air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now
Charleston, SC · Air quality right now
The air quality index in Charleston, SC is 33 (Good) right now — safe for outdoor activity.
Is it safe to be outside in Charleston today?
AQI 33 Yes — air quality is Good
Air is clean — great for outdoor activity.Main pollutant: PM2.5Observed 11:00 AM EDT
Pollutants right now
- PM2.57.4 µg/m³Main pollutantfine particles — smoke, exhaust, soot
- PM109.8 µg/m³coarse particles — dust, pollen, ash
- Ozone86 µg/m³smog — builds on hot, sunny days
- NO₂1.9 µg/m³nitrogen dioxide — traffic, combustion
ExerciseOK to run — no air-quality limits on outdoor exercise.
How to read Charleston’s air quality
Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.
Air quality over time in Charleston
Across the EPA’s county records from 2020 to 2025, Charleston’s cleanest year was 2020 (median AQI 43) and its most polluted was 2021 (median AQI 48); the typical (median) day has held roughly steady since 2020.
| Year | Median AQI | Unhealthy+ | Main pollutant | USG | Moderate | Good |
|---|---|---|---|---|---|---|
| 2020 | 43 | 0 | PM2.5 | 1 | 101 | 264 |
| 2021 | 48 | 0 | PM2.5 | 0 | 168 | 197 |
| 2022 | 47 | 0 | PM2.5 | 0 | 156 | 209 |
| 2023 | 47 | 0 | PM2.5 | 0 | 153 | 212 |
| 2024 | 43 | 0 | PM2.5 | 0 | 97 | 269 |
| 2025 | 47 | 0 | PM2.5 | 1 | 142 | 222 |
“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.
Frequently asked
- What was the worst year for air quality in Charleston?
- In the EPA's 2020–2025 county records, 2025 had the most days above AQI 100: 1 day (1 Unhealthy for Sensitive Groups, 0 Unhealthy or worse). The highest median AQI came in 2021 (48; 2025's was 47).
- How many unhealthy air days does Charleston have?
- Across 2020–2025, under 1% of the days reported for Charleston's county had an AQI above 100 (2 of 2192), fewer than one a year on average. 2025 had 1 day.
- What's the main air pollutant in Charleston?
- PM2.5: it drove Charleston's county AQI on the most days in every year of the EPA's 2020–2025 records.