Metro area air quality · 2025

Winston-Salem, NC

Median AQI 52 (Moderate). 41.6% of monitored days rated Good across this metro's EPA monitoring network.

52
Median AQI
41.6%
Good-air days
0
Unhealthy days
7%
Cleaner than US metros

Winston-Salem, NC posted a 2025 median AQI of 52 (Moderate) with 41.6% Good days

According to the U.S. EPA Air Quality System, the Winston-Salem, NC CBSA recorded a median AQI of 52 across 365 monitored days in 2025, with 41.6% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US metros
The Winston-Salem, NC CBSA's 41.6% Good-day share places it cleaner than 7% of US metros in 2025.
Closest median-AQI peer
Augusta-Richmond County, GA-SC (46.0% Good, median AQI 52) is the closest nationwide median-AQI peer to Winston-Salem, NC.
2020–2025 Good-day shift
Winston-Salem, NC's Good-day share moved -15.5 points from 2020 to 2025 (median AQI +5).
Median AQI
Median AQI: 52

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

Winston-Salem, NC lands in the lower Good-day tercile (41.6% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs moderate, among the more polluted US metros, with a median AQI of 52 and 41.6% of 365 monitored days in the Good band.

52
median AQI · Moderate
41.6%
days rated Good
7%
cleaner than US metros
100
worst single reading

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

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Winston-Salem, NC metro's Good-day share fell from 52.2% to 41.6% between the 2024 and 2025 EPA annual releases, a change of -10.6 percentage points.
  • Winston-Salem, NC metro's peak single-day AQI fell from 122 to 100 between the 2024 and 2025 EPA annual releases, a change of -22 points.

Compared against 362 monitored days in 2024 and 365 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Winston-Salem, NC lands in the lower Good-day tercile (41.6% Good), a thinner clean-air share than most CBSA peers here. Signature read: 41.6% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 52 over 365 measured days in 2025 (Moderate / Poor). The monitored-day split lands at 152 Good (42%), 213 Moderate (58%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 64; the highest single-day reading hit 100 (Moderate).

Across 2020–2025, Good-day share shifted -15.5 points and median AQI moved +5 (worsening). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Augusta-Richmond County, GA-SC (46.0% good, AQI 52); Beaumont-Port Arthur, TX (41.4% good, AQI 52); Birmingham-Hoover, AL (43.0% good, AQI 52).

Health effects of air pollution →

Air Quality Summary

Median AQI

52

Moderate

Good Days

41.6%

152 of 365 days

Max AQI

100

Moderate

Health Grade

Poor

90th pct: 64

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

152

42%

Moderate

213

58%

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 41.6% 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 typical
Winston-Salem, NC 41.6%
Augusta-Richmond County, GA-SC 46.0%
Typical US metro 70.6%
Median AQI worse than typical
Winston-Salem, NC 52
Augusta-Richmond County, GA-SC 52
Typical US metro 41
Unhealthy days / yr better than typical
Winston-Salem, NC 0
Augusta-Richmond County, GA-SC 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Winston-Salem, NC metro. Highest Good-day share: 2020 (57.1%, 209 of 366 monitored 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 152 213 0 52

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Winston-Salem, NC (52).

Augusta-Richmond County, GA-SC

Median AQI 52 · 46.0% Good-day share

52

Beaumont-Port Arthur, TX

Median AQI 52 · 41.4% Good-day share

52

Birmingham-Hoover, AL

Median AQI 52 · 43.0% Good-day share

52

Charlotte-Concord-Gastonia, NC-SC

Median AQI 52 · 46.0% Good-day share

52

El Dorado, AR

Median AQI 52 · 41.8% Good-day share

52

Grand Rapids-Wyoming, MI

Median AQI 52 · 41.9% Good-day share

52

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Winston-Salem, NC's 0 (independent of median AQI).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Frequently Asked Questions

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 100.
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 52, rated "Moderate." 41.6% of monitored days (152 out of 365) had good air quality in 2025.
Is air quality in Winston-Salem, NC getting better or worse? ▼
Air quality in the Winston-Salem, NC metro is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 57.1% (209 of 366 days). Lowest qualifying Good-day share: 2023 at 40.9% (147 of 359 days).
What does AQI 52 mean for health? ▼
An AQI of 52 is "Moderate", air quality is acceptable, but some pollutants may pose a moderate health concern for a small number of sensitive individuals.
How does Winston-Salem, NC compare to other metro areas? ▼
The Winston-Salem, NC metro has 41.6% good air days. Similar metros: Augusta-Richmond County, GA-SC (46.0% good), Beaumont-Port Arthur, TX (41.4% good), Birmingham-Hoover, AL (43.0% good).
What is the 90th percentile AQI for Winston-Salem, NC? ▼
The 90th percentile AQI for the Winston-Salem, NC metro area is 64, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 100 (Moderate).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Winston-Salem, NC, 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, Winston-Salem, NC · 2020–2025