Charleston Best & Worst AQI Days: Air Quality Guide
The worst air quality day on record for Charleston (Charleston, WV area) was June 29, 2023, when the daily AQI reached 153 (Unhealthy), set by fine particulate matter (PM2.5), in wildfire smoke season. Across 2,539 monitored days in 2019–2025, 1 of the 10 worst days was Unhealthy (AQI 151+) or worse; 6 of the 10 were driven by ground-level ozone and 4 by fine particulate matter (PM2.5), and 4 of them fell in 2021. The cleanest day was May 13, 2019 at AQI 0 (Good); the 10 best days span 2 different years.
Extra Protection for Charleston Homes
Air quality in Charleston is moderate (AQI 55), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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When were Charleston's worst and best air quality days?
Worst: June 29, 2023, AQI 153 (Unhealthy, PM2.5). Best: May 13, 2019, AQI 0 (Good). Based on 2,539 EPA-monitored days in the Charleston, WV area, 2019–2025.
- ✓1 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 88 (Moderate).
- ✓Ground-level ozone drove 6 of the 10 worst days.
- ✓2021 accounts for 4 of the 10 worst days.
Frequently asked questions
What was the worst air quality day in Charleston?▾
June 29, 2023: the Charleston, WV area's daily AQI hit 153 (Unhealthy), driven by fine particulate matter (PM2.5), in wildfire smoke season. That is the highest of 2,539 monitored days in 2019–2025.
What was the best air quality day in Charleston?▾
May 13, 2019, with a daily AQI of 0 (Good). The daily AQI is the highest reading from any monitor in the area, so even the cleanest day reflects the area's worst monitor.
What was Charleston's worst air quality day in 2025?▾
June 23, 2025, AQI 69 (Moderate), set by fine particulate matter (PM2.5).
Which pollutant causes Charleston's worst air days?▾
Ground-level ozone set the AQI on 6 of the 10 worst days; fine particulate matter (PM2.5) on 4. The tables above list the defining pollutant for every day.
Charleston's 10 worst air quality days, 2019–2025
Highest daily AQI recorded for the Charleston, WV area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2023 page) | 153 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 2 | (2021 page) | 97 | Moderate | O3 — ground-level ozone, in peak ozone season |
| 3 | (2021 page) | 93 | Moderate | PM2.5 — fine particulate matter (PM2.5) |
| 4 | (2019 page) | 93 | Moderate | O3 — ground-level ozone, in peak ozone season |
| 5 | (2024 page) | 90 | Moderate | O3 — ground-level ozone, in peak ozone season |
| 6 | (2022 page) | 90 | Moderate | O3 — ground-level ozone |
| 7 | (2021 page) | 90 | Moderate | O3 — ground-level ozone, in peak ozone season |
| 8 | (2021 page) | 90 | Moderate | PM2.5 — fine particulate matter (PM2.5) |
| 9 | (2019 page) | 90 | Moderate | O3 — ground-level ozone, in peak ozone season |
| 10 | (2023 page) | 88 | Moderate | PM2.5 — fine particulate matter (PM2.5) |
Worst day of each year in Charleston
The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.
| Year | Worst day | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 2019 | 93 | Moderate | O3 — ground-level ozone, in peak ozone season | |
| 2020 | 85 | Moderate | PM2.5 — fine particulate matter (PM2.5) | |
| 2021 | 97 | Moderate | O3 — ground-level ozone, in peak ozone season | |
| 2022 | 90 | Moderate | O3 — ground-level ozone | |
| 2023 | 153 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2024 | 90 | Moderate | O3 — ground-level ozone, in peak ozone season | |
| 2025 | 69 | Moderate | PM2.5 — fine particulate matter (PM2.5) |
Charleston's 10 best air quality days, 2019–2025
Lowest daily AQI recorded for the Charleston, WV area. Ties are listed most recent first.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2019 page) | 0 | Good | CO — carbon monoxide |
| 2 | (2019 page) | 1 | Good | CO — carbon monoxide |
| 3 | (2019 page) | 1 | Good | CO — carbon monoxide |
| 4 | (2019 page) | 1 | Good | CO — carbon monoxide |
| 5 | (2019 page) | 1 | Good | CO — carbon monoxide |
| 6 | (2019 page) | 2 | Good | CO — carbon monoxide |
| 7 | (2019 page) | 2 | Good | CO — carbon monoxide |
| 8 | (2019 page) | 2 | Good | CO — carbon monoxide |
| 9 | (2024 page) | 3 | Good | CO — carbon monoxide |
| 10 | (2019 page) | 3 | Good | CO — carbon monoxide |
Right now in Charleston
The latest EPA AirNow observation puts Charleston's AQI at 55 (PM2.5). The days above are historical records, not today's reading.
View current Charleston air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Charleston, WV), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.