Air Quality in Winston-Salem, North Carolina — Live
Live readings from PurpleAir sensors across Winston-Salem — with free alerts the moment ozone or particle pollution climbs.
AQI 38 from 2 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Winston-Salem, North Carolina is AQI 38 — Good and falling — with PM2.5 at 7.0 µg/m³, the median of 2 live PurpleAir sensors reading 30 to 47. Canairy's verdict: Breathe easy.
For scale, that PM2.5 reading is below the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Winston-Salem and Kernersville, Clemmons, Lewisville, Rural Hall. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Winston-Salem
The sensors Canairy reads in Winston-Salem agree right now — all 2 sit in the Good band, a 17-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 2.1 mi ENE | 30 | Good |
| 4.5 mi W | 47 | Good |
Winston-Salem's air is unremarkable for most of the year — this is Piedmont North Carolina, not a smoke-prone canyon or a coastal refinery town. The real pattern shows up in summer, when the Piedmont Triad's own environmental office declares Code Orange ozone action days on the hottest, stillest afternoons, covering Forsyth County and eight neighboring counties at once.
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What the air in Winston-Salem is doing next
| When | AQI | Expected air quality | Main pollutant |
|---|---|---|---|
| Today | 42 | Good | PM2.5 |
| Tomorrow | 47 | Good | PM2.5 |
| Wednesday | 50 | Good | PM2.5 |
Air quality levels have improved and returned to the GREEN range as temperatures have cooled down and highs should hold in the 60s for the next few days. Lows will drop into the upper 40sand winds should be out of the northeast through Monday. AQI readings will continue to be in the GREEN range as this clean air mass controls the weather in the region. AQI levels may increase into the upper GREEN/lower YELLOW range later in the week. (Bodenhamer)
Forecast from EPA AirNow for the Forsyth County-Winston-Salem-Greensboro-High Point reporting area. Canairy watches the live sensors against it and tells you when the air actually crosses your threshold, rather than leaving you to check.
Why Winston-Salem gets Code Orange days in summer
The Forsyth County Office of Environmental Assistance and Protection issued a Code Orange ozone action day on May 20, 2026, warning of high temperatures in the 90s, bright sunlight, low humidity, and a stagnant air mass — the exact recipe that cooks vehicle and industrial exhaust into ground-level ozone. It happened again on July 16, 2026, this time described as unhealthy for sensitive groups under a similar mix of heat, sun, and stalled air. Both alerts covered all nine Triad counties at once — Forsyth, Guilford, Alamance, Davidson, Randolph, Rockingham, Caswell, Davie, and Stokes — because ozone forms regionally and does not respect county lines.
On these days, officials ask that people who are older, are children, or have heart or lung disease limit prolonged outdoor exertion and take frequent breaks. Everyone else gets asked to help by driving less, skipping the gas-powered lawn mower, and holding off on open burning until the alert lifts, because it is mostly cars, mowers, and stationary sources that supply the raw ingredients ozone needs to form on a hot, sunny, windless afternoon.
Forsyth County's ozone problem is not new
The EPA first designated Forsyth County a moderate nonattainment area for ozone back in November 1991, grouped with Guilford and Davidson counties and part of Davie County. County records describe the years that followed as rough: by the late 1990s the Triad was racking up 30 to 35 exceedances of the ozone standard in a single ozone season. Cleaner vehicle engines, tighter industrial permits, and stricter fuel rules turned that around, and the numbers started dropping around 2004 and 2005.
The improvement was real, but it was not a finish line. The American Lung Association's 2026 State of the Air report, built on 2022-2024 monitoring data, still gives the Greensboro-Winston-Salem-High Point metro a C for ozone, ranking it 100th worst nationally, and a D for short-term particle pollution, ranking 76th worst. Winston-Salem sits inland on the Piedmont plateau with no mountains or valley walls to trap anything; the air here turns bad because of heat and stillness, not because the terrain bottles it up.
US 52 and Business 40 run pollution straight through downtown
Winston-Salem's core sits at the crossing of US 52 and Business 40, the urban freeway link that ties I-77, I-40, and I-85 together through the middle of the city. Traffic on that corridor is a steady year-round source of the nitrogen oxides and fine particles that add to the ozone mix on summer afternoons and to the particle-pollution numbers the rest of the year. The city's tobacco and textile manufacturing history — R.J. Reynolds and Hanes both trace their roots here — has faded as a smokestack source, but the highway network that grew up to move goods and workers around those old plants never went away.
That combination is why a single number for the whole city can be misleading. A reading taken a few blocks from the US 52 or I-40 interchange downtown can run noticeably higher than one out in Clemmons or Lewisville on the same afternoon. Checking the sensor near the place you actually are, not just the citywide average, is the difference between an accurate call and a guess.
Winston-Salem air quality FAQ
What is the air quality in Winston-Salem right now?
As of November 2, 2026 at 10:05 AM EST, the air quality in Winston-Salem, North Carolina is AQI 38 — Good — with PM2.5 at 7.0 µg/m³, the median of 2 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Winston-Salem get ozone action days in summer?
Hot, sunny, windless afternoons let vehicle exhaust and other emissions cook into ground-level ozone faster than it can disperse. The Forsyth County Office of Environmental Assistance and Protection declared Code Orange ozone action days on May 20 and July 16, 2026, both driven by 90-degree heat, strong sun, and a stagnant air mass across the nine-county Piedmont Triad region.
Has Winston-Salem's air quality always been this way?
It has actually improved. The EPA designated Forsyth County a nonattainment area for ozone in 1991, and by the late 1990s the Triad was seeing 30 to 35 days a year over the ozone standard. Cleaner engines and tighter industrial rules brought that down starting around 2004, though the region still earns a C for ozone and a D for particle pollution in the American Lung Association's 2026 report.
What the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 2 curated PurpleAir sensors Canairy tracks in and around Winston-Salem, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
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Air quality near Winston-Salem
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