Metro area air quality · 2025

Winston-Salem, NC

Median AQI 51 (Moderate). 45.8% of monitored days rated Good across this metro's EPA monitoring network.

51
Median AQI
45.8%
Good-air days
0
Unhealthy days
9%
Cleaner than US metros

Aggregated from EPA Air Quality System (2025), 271 monitored days. EPA AQS →

The verdict

The Winston-Salem, NC metro runs moderate on the EPA scale, among the more polluted US metros, a median AQI of 51 with 45.8% of 271 monitored days in the Good band.

51
median AQI · Moderate
45.8%
days rated Good
9%
cleaner than US metros
90
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Insights: Winston-Salem, NC metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 51 over 271 measured days in 2025, which corresponds to a Moderate band and a Poor metro-wide health grade. The monitored-day split lands at 124 Good days (46%), 147 Moderate (54%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 66 while the highest single-day reading hit 90 (Moderate). Metro residents averaged roughly 13.7 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -85 and the median AQI moved +4 points, which classifies the multi-year trajectory as worsening. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Augusta-Richmond County, GA-SC (47.6% good, AQI 51); Canton-Massillon, OH (49.5% good, AQI 51); Carlsbad-Artesia, NM (46.9% good, AQI 51).

Air Quality Summary

Median AQI

51

Moderate

Good Days

45.8%

124 of 271 days

Max AQI

90

Moderate

Health Grade

Poor

90th pct: 66

AQI Day Breakdown (2025)

Distribution of 271 monitored days across EPA AQI categories.

Good

124

46%

Moderate

147

54%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Poor

The Winston-Salem, NC metro area's air quality is rated Poor based on 45.8% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Winston-Salem, NC metro compare?

How Winston-Salem, NC compares

Good-day share worse than US avg
Winston-Salem, NC 45.8%
Augusta-Richmond County, GA-SC 47.6%
US average 71.3%
Median AQI worse than US avg
Winston-Salem, NC 51
Augusta-Richmond County, GA-SC 51
US average 41
Unhealthy days / yr better than US avg
Winston-Salem, NC 0
Augusta-Richmond County, GA-SC 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Winston-Salem, NC metro. Best year: 2020 (209 good days).

Year Good Moderate Unhealthy Median AQI
2020 209 157 0 47
2021 183 179 0 50
2022 183 181 0 50
2023 147 211 1 53
2024 189 173 0 50
2025 124 147 0 51

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Winston-Salem, NC.

Augusta-Richmond County, GA-SC

AQI 51 · 47.6% good

51

Canton-Massillon, OH

AQI 51 · 49.5% good

51

Carlsbad-Artesia, NM

AQI 51 · 46.9% good

51

Charlotte-Concord-Gastonia, NC-SC

AQI 51 · 46.9% good

51

Jacksonville, FL

AQI 51 · 49.8% good

51

Macon, GA

AQI 51 · 49.5% good

51

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Winston-Salem, NC metro area? ▼
The Winston-Salem, NC metro area has a median Air Quality Index (AQI) of 51, rated "Moderate." 45.8% of monitored days (124 out of 271) had good air quality in 2025.
How many unhealthy air days does Winston-Salem, NC have? ▼
In 2025, the Winston-Salem, NC metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 90.
Is air quality in Winston-Salem, NC getting better or worse? ▼
Air quality in the Winston-Salem, NC metro is worsening based on 5-year trends (2020-2025). Best year: 2020 with 209 good days. Worst year: 2025 with 124 good days.
What does AQI 51 mean for health? ▼
An AQI of 51 is "Moderate", air quality is acceptable, but some pollutants may pose a moderate health concern for a small number of sensitive individuals.
What is the 90th percentile AQI for Winston-Salem, NC? ▼
The 90th percentile AQI for the Winston-Salem, NC metro area is 66, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 90 (Moderate).
How does Winston-Salem, NC compare to other metro areas? ▼
The Winston-Salem, NC metro has 45.8% good air days. Similar metros: Augusta-Richmond County, GA-SC (47.6% good), Canton-Massillon, OH (49.5% good), Carlsbad-Artesia, NM (46.9% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025

Every figure on PlainAir is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.