Median AQI
52
Moderate
Michigan · County air quality · 2025
Wayne County, Michigan
Median AQI 52 (Moderate). 46.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 52
- Median AQI
- 46.4%
- Good-air days
- 3
- Unhealthy days
- 5%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Wayne County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 52 with 46.4% of 304 monitored days in the Good band, driven mainly by PM2.5.
- 52
- median AQI · Moderate
- 46.4%
- days rated Good
- PM2.5
- main pollutant
- 5%
- cleaner than US counties
3 days reached Unhealthy or worse; the worst single reading hit AQI 156.
Data updated July 2026
- Good · 141 d · 46.4%
- Moderate · 153 d · 50.3%
- USG · 7 d · 2.3%
- Unhealthy · 3 d · 1.0%
How did Wayne County's air break down in 2025?
Across 304 monitored days, 141 fell in the Good band (AQI 0–50) and 3 reached Unhealthy or worse. The worst single day peaked at AQI 156 (Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 304 days monitored. Median AQI: 52 (Moderate).
Insights: Wayne County, Michigan. EPA monitors recorded a median Air Quality Index of 52 across 304 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 141 (46%) fell in the Good band (AQI 0–50), 153 (50%) registered Moderate readings, and 7 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 72, while the worst single-day peak hit 156 (Unhealthy). Residents averaged about 13.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (192 days), Ozone (108 days), NO2 (3 days), PM10 (1 days). Across the 2020–2025 trend window, good days shifted by +23 and the median AQI moved -3 points, placing the multi-year trajectory at improving. Residents and visitors experienced 3 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Allegan (71.2% good, AQI 43); Bay (71.8% good, AQI 38); Benzie (91.1% good, AQI 35); Berrien (80.9% good, AQI 41); Cass (85.3% good, AQI 40); Clinton (90.2% good, AQI 39).
Air Quality Summary
Good Days
46.4%
141 of 304 monitored days
-28.6pp vs 75% target
Max AQI Recorded
156
Unhealthy
Health Grade
Poor
90th-pct AQI 72
Wayne County, Good days share 46.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Wayne County, Unhealthy-or-worse share 1.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 304 monitored days across EPA AQI categories.
Good
141
46%
Moderate
153
50%
USG
7
2%
Unhealthy
3
1%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Wayne County.
- PM2.5 · 192 days · 63.2%
- Ozone · 108 days · 35.5%
- NO₂ · 3 days · 1.0%
- PM10 · 1 days · 0.3%
Health Impact Assessment
Poor
Wayne County's air quality is rated Poor based on 46.4% good air days. There were 3 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 7 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 156. Sensitive groups should monitor real-time conditions at AirNow.gov.
The dominant pollutant is PM2.5, driving AQI on 192 of 304 monitored days.
5-Year Air Quality Trend
Air quality is improving in Wayne County. Best year: 2025 (141 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 118 | 238 | 8 | 2 | 55 | 188 |
| 2021 | 86 | 275 | 4 | 0 | 58 | 118 |
| 2022 | 63 | 287 | 15 | 0 | 58 | 131 |
| 2023 | 70 | 272 | 19 | 3 | 61 | 226 |
| 2024 | 120 | 238 | 7 | 1 | 55 | 181 |
| 2025 | 141 | 153 | 7 | 3 | 52 | 156 |
How does Wayne County compare?
How Wayne County compares
Good-day share worse than US avg
Wayne County 46.4%
Allegan County, Michigan 71.2%
US average 76.5%
Median AQI worse than US avg
Wayne County 52
Allegan County, Michigan 43
US average 38
Unhealthy days / yr worse than US avg
Wayne County 3
Allegan County, Michigan 1
US average 0
Other Counties in Michigan
Air quality comparison for nearby counties in Michigan.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Wayne County.
Duval County, Florida
AQI 52 · 40.7% good
Hinds County, Mississippi
AQI 52 · 43.4% good
Jefferson County, Texas
AQI 52 · 42.4% good
McLennan County, Texas
AQI 52 · 43.4% good
Orange County, California
AQI 52 · 44.5% good
Union County, Arkansas
AQI 52 · 44.0% good
What Wayne County's air means for you
On most days the air here is fine, but PM2.5 drives 3 unhealthy-or-worse days a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 52 means for exposure. Health guidance
- See how Wayne County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Wayne County with its Michigan neighbours before drawing a conclusion about the region. All of Michigan
Based on 304 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Wayne County, Michigan? ▼
Wayne County has a median Air Quality Index (AQI) of 52, rated "Moderate." 46.4% of monitored days (141 out of 304) had good air quality in 2025.
What is the main pollutant in Wayne County? ▼
The primary pollutant in Wayne County is Fine Particles (PM2.5), which was the main AQI driver on 192 days (63% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Wayne County have? ▼
In 2025, Wayne County recorded 3 unhealthy air days (3 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 156.
Is the air quality in Wayne County getting better or worse? ▼
Air quality in Wayne County is improving based on 5-year trends (2020-2025). Best year: 2025 with 141 good days. Worst year: 2022 with 63 good days.
What does AQI 52 mean for health? ▼
Wayne County's median AQI of 52 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Wayne County compare to other counties in Michigan? ▼
Wayne County has 46.4% good air days. Nearby counties in Michigan: Allegan (71.2% good), Bay (71.8% good), Benzie (91.1% good), Berrien (80.9% good), Cass (85.3% good), Clinton (90.2% good).
What is the 90th percentile AQI in Wayne County? ▼
The 90th percentile AQI for Wayne County is 72, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 156 (Unhealthy).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
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.