What Is the Air Quality in Winchester City, Virginia?
Winchester City, Virginia has an Air Quality Grade of A (excellent) with a 5-year median AQI of 7. The dominant pollutant is Coarse Particulate Matter (PM10), and air quality has been improving over the past decade.
Winchester City, Virginia Air Quality Snapshot
| Air Quality Grade | A85/100 |
| 5-Year Median AQI | 7 (Good) |
| Most Recent Median AQI (2020) | 6 (Good) |
| Dominant Pollutant | Coarse Particulate Matter (PM10) |
| 10-Year Trend | Improving (-0.50 AQI/yr) |
| Unhealthy Days (last 5 yr) | 0 |
| Virginia Rank | #3 of 32 |
What Does the A Grade Mean?
Winchester City, Virginia earns an A — it is among the cleanest U.S. cities tracked by EPA monitoring, with median AQI averaging just 7 over the past five years. Days in the "Good" category dominate the calendar; air-quality alerts are rare.
Winchester City, Virginia's 5-year median AQI of 7 is 34 points below the national average of 41 — meaningfully cleaner than the typical U.S. metro tracked here. Within Virginia, Winchester City, Virginia runs cleaner than the state average of 33 — a positive signal that local conditions (terrain, wind patterns, emission sources) are working in residents' favor.
For context within Virginia: Alexandria City, Virginia currently holds the state's cleanest grade (A, AQI 6), while Richmond City, Virginia sits at the bottom (C, AQI 42).
What's in Winchester City, Virginia's Air?
The dominant pollutant in Winchester City, Virginia is Coarse Particulate Matter (PM10). Coarse particulate matter — particles up to 10 micrometers across — typically comes from dust, construction sites, agriculture, unpaved roads, and natural sources like windblown soil. PM10 is less hazardous than PM2.5 because the larger particles do not penetrate as deeply into the lungs, but high levels still aggravate asthma and irritate airways.
Days by Dominant Pollutant (2020)
| Pollutant | Days as Dominant | Share of Year |
|---|---|---|
| Coarse Particulate Matter (PM10) | 58 | 100% |
Is the Air Getting Better or Worse?
Air quality in Winchester City, Virginia has been improving over the past decade, with median AQI dropping by roughly 0.5 points per year. That is consistent with the broader national pattern — most U.S. metros have seen steady reductions in particulate and ozone pollution since the 2010s as cleaner vehicles and power plants come online.
In 2014, Winchester City, Virginia posted a median AQI of 8. By 2020 that figure was 6 — a drop of 2 AQI points cleaner across 7 years of EPA records.
Year-by-Year AQI in Winchester City, Virginia
| Year | Median AQI | Good Days | Unhealthy Days | Dominant Pollutant |
|---|---|---|---|---|
| 2014 | 8 | 61 | 0 | PM10 |
| 2015 | 11 | 59 | 0 | PM10 |
| 2016 | 10 | 59 | 0 | PM10 |
| 2017 | 11 | 59 | 0 | PM10 |
| 2018 | 8 | 60 | 0 | PM10 |
| 2019 | 8 | 57 | 0 | PM10 |
| 2020 | 6 | 58 | 0 | PM10 |
Health Context for Winchester City, Virginia
Across the past five years, this area has logged just 0 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 0 days per year, or roughly one every other month. That is a low count by national standards.
For most healthy adults, current air quality in this area does not require any change in behavior. People with severe asthma, COPD, or recent cardiac events should still keep an eye on daily AQI alerts, especially during wildfire season. PM10 is largely a near-source pollutant — staying upwind of busy roads, construction, and unpaved areas can substantially reduce exposure.
How This Grade Is Calculated
The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.
Winchester City, Virginia has an Air Quality Grade of A (excellent) with a 5-year median AQI of 7. The dominant pollutant is Coarse Particulate Matter (PM10), and air quality has been improving over the past decade.
This answer pulls from the EPA Air Quality System (AQS), the authoritative federal source for U.S. air quality and pollution monitoring. The headline number above is the direct answer; what follows is the additional context most readers need to use the answer for a real decision rather than just a fact lookup.
A practical caveat: the headline answer above reflects the most recent the EPA Air Quality System (AQS) vintage; underlying data is often revised for months after first publication, and the right reference for any specific decision is whichever vintage is current at the time of the decision. The as-of date is stamped on every page.
Source: EPA Outdoor Air Quality Data, 2026.