Charleston, WV Air Quality in September
Across 2019–2025, Charleston's September air quality had a median AQI of 41 (Good) over 209 monitored days in the Charleston, WV area. 0.0% of September days (0 of 209) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 56.5% of days. The cleanest September on record here was 2022 (median AQI 32, 0 days above 100) and the worst was 2019 (median 50, 0 days above 100, peak AQI 64).
- Good: 77.0%
- Moderate: 23.0%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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.
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How is the air in Charleston in September?
Good on a typical day: median AQI 41 across 2019–2025, with 0.0% of September days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓77.0% of September days were Good (AQI 0–50), 23.0% Moderate (51–100).
- ✓0 days of 209 reached AQI 101+; the September peak was 64.
- ✓Best September: 2022; worst September: 2019.
Frequently asked questions
What is the air quality like in Charleston in September?▾
Across 2019–2025, the median daily AQI in Charleston in September was 41 (Good). 77.0% of days were Good, 23.0% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 209 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Charleston?▾
A typical September day in Charleston sits in the Good range (median AQI 41), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of September days reached AQI 101+ in 2019–2025.
Which pollutant causes Charleston's September air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 56.5% of September days in Charleston. The highest September AQI recorded in 2019–2025 was 64 (Moderate), in 2019.
Charleston September air quality, year by year
Charleston September air quality by year (Charleston, WV, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 30 | 50 | 0 | 64 | O3 |
| 2020 | 30 | 35 | 0 | 55 | O3 |
| 2021 | 30 | 42 | 0 | 58 | PM2.5 |
| 2022cleanest | 29 | 32 | 0 | 56 | PM2.5 |
| 2023 | 30 | 38 | 0 | 53 | O3 |
| 2024 | 30 | 39 | 0 | 59 | O3 |
| 2025 | 30 | 49 | 0 | 56 | PM2.5 |
What September air means in Charleston
A typical September day in Charleston sits in the Good range (median AQI 41), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of September days reached AQI 101+ in 2019–2025.
September's median AQI of 41 is in line with Charleston's whole-year median of 41, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Charleston runs in line with the national September norm; 0.0% of its September days topped AQI 100 versus 2.7% nationally (below average).
September is part of Charleston's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Charleston
The latest EPA AirNow observation puts Charleston's AQI at 55 (PM2.5). The figures above are multi-year month statistics, 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.