Winston-Salem Air Quality in September
Across 2019–2025, Winston-Salem's September air quality had a median AQI of 51 (Moderate) over 210 monitored days in the Winston-Salem, NC area. 0.0% of September days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 60.0% of days. The cleanest September on record here was 2022 (median AQI 41, 0 days above 100) and the worst was 2019 (median 57, 0 days above 100, peak AQI 97).
- Good: 49.5%
- Moderate: 50.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Extra Protection for Winston-Salem Homes
Air quality in Winston-Salem is moderate (AQI 52), 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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Winston-Salem in September?
Moderate on a typical day: median AQI 51 across 2019–2025, with 0.0% of September days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓49.5% of September days were Good (AQI 0–50), 50.5% Moderate (51–100).
- ✓0 days of 210 reached AQI 101+; the September peak was 100.
- ✓Best September: 2022; worst September: 2019.
Frequently asked questions
What is the air quality like in Winston-Salem in September?▾
Across 2019–2025, the median daily AQI in Winston-Salem in September was 51 (Moderate). 49.5% of days were Good, 50.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Winston-Salem?▾
A typical September day in Winston-Salem is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of September days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Winston-Salem's September air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 60.0% of September days in Winston-Salem. The highest September AQI recorded in 2019–2025 was 100 (Moderate), in 2019.
Winston-Salem September air quality, year by year
Winston-Salem September air quality by year (Winston-Salem, NC, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 30 | 57 | 0 | 97 | O3 |
| 2020 | 30 | 49 | 0 | 74 | PM2.5 |
| 2021 | 30 | 49 | 0 | 67 | O3 |
| 2022cleanest | 30 | 41 | 0 | 74 | PM2.5 |
| 2023 | 30 | 53 | 0 | 97 | PM2.5 |
| 2024 | 30 | 41 | 0 | 64 | O3 |
| 2025 | 30 | 52 | 0 | 100 | PM2.5 |
What September air means in Winston-Salem
A typical September day in Winston-Salem is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of September days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
September's median AQI of 51 is in line with Winston-Salem's whole-year median of 50, 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 Winston-Salem runs above the national September norm; 0.0% of its September days topped AQI 100 versus 2.7% nationally (below average).
September is part of Winston-Salem's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Winston-Salem
The latest EPA AirNow observation puts Winston-Salem's AQI at 52 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Winston-Salem air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Winston-Salem, NC), 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.