Median AQI
54
Moderate
Michigan · County air quality · 2025
Wayne County, Michigan
Median AQI 54 (Moderate). 36.2% of monitored days rated Good, direct from EPA Air Quality System stations.
- 54
- Median AQI
- 36.2%
- Good-air days
- 3
- Unhealthy days
- 3%
- Cleaner than US counties
Wayne County's 2025 annual median AQI is 54 (Moderate), with 36.2% Good days
According to the U.S. EPA Air Quality System, Wayne County, Michigan posted a 2025 median AQI of 54 (Moderate) across 365 monitored days, with 36.2% rated Good and 3 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Wayne County's 36.2% Good-day share places it cleaner than 3% of US counties in 2025.
- Closest median-AQI peer
- Hamilton County (34.3% Good, median AQI 54) is the closest nationwide median-AQI peer to Wayne County.
- 2020–2025 trend
- Wayne County's floor-qualifying Good-day share is improving from 2020 to 2025 (32.2% → 36.2%).
- Median AQI
- Median AQI: 54
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 54 with 36.2% of 365 monitored days in the Good band, driven mainly by PM2.5.
- 54
- median AQI · Moderate
- 36.2%
- days rated Good
- PM2.5
- main pollutant
- 3%
- cleaner than US counties
3 days reached Unhealthy or worse; the worst single reading hit AQI 156.
Annual release change
What changed in the 2025 EPA annual release
- Wayne County's Good-day share rose from 32.8% to 36.2% between the 2024 and 2025 EPA annual releases, a change of +3.4 percentage points.
- Wayne County's peak single-day AQI fell from 181 to 156 between the 2024 and 2025 EPA annual releases, a change of -25 points.
- Wayne County's Unhealthy-category days rose from 1 to 3 between the 2024 and 2025 EPA annual releases, a change of +2 days.
Data updated August 2026
- Good · 132 d · 36.2%
- Moderate · 222 d · 60.8%
- USG · 8 d · 2.2%
- Unhealthy · 3 d · 0.8%
How did Wayne County's air break down in 2025?
Across 365 monitored days, 132 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). 365 days monitored. Median AQI: 54 (Moderate).
Insights: Wayne County, Michigan. EPA monitors recorded a median Air Quality Index of 54 across 365 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 132 (36%) fell in the Good band (AQI 0–50), 222 (61%) registered Moderate readings, and 8 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 75, while the worst single-day peak hit 156 (Unhealthy). Residents averaged about 10.8 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (299 days), Ozone (60 days), PM10 (3 days), NO2 (3 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +3.9 points and the median AQI moved -1 points, placing the multi-year trajectory at improving. The annual record contains 3 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Allegan (63.9% good, AQI 44); Bay (70.4% good, AQI 39); 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
36.2%
132 of 365 monitored days
-38.8pp vs 75% target
Max AQI Recorded
156
Unhealthy
Health Grade
Poor
90th-pct AQI 75
Wayne County, Good days share 36.2%
National avg
Share of monitored days at AQI 0-50 (Good band).
Wayne County, Unhealthy-or-worse share 8.2%
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 365 monitored days across EPA AQI categories.
Good
132
36%
Moderate
222
61%
USG
8
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 · 299 days · 81.9%
- Ozone · 60 days · 16.4%
- PM10 · 3 days · 0.8%
- NO₂ · 3 days · 0.8%
Health Impact Assessment
Poor
Wayne County's air quality is rated Poor based on 36.2% good air days. There were 3 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 8 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 299 of 365 monitored days.
5-Year Air Quality Trend
Air quality is improving in Wayne County. Highest Good-day share: 2025 (36.2%, 132 of 365 monitored 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 | 132 | 222 | 8 | 3 | 54 | 156 |
How does Wayne County compare?
How Wayne County compares
Good-day share worse than US avg
Wayne County 36.2%
Hamilton County, Ohio 34.3%
US average 76.0%
Median AQI worse than US avg
Wayne County 54
Hamilton County, Ohio 54
US average 39
Unhealthy days / yr worse than US avg
Wayne County 3
Hamilton County, Ohio 1
US average 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Wayne County (54), not geographic neighbors.
Hamilton County, Ohio
Median AQI 54 · 34.3% Good-day share
Marion County, Indiana
Median AQI 54 · 40.0% Good-day share
Pima County, Arizona
Median AQI 54 · 33.7% Good-day share
Butler County, Ohio
Median AQI 55 · 33.1% Good-day share
Cook County, Illinois
Median AQI 53 · 40.8% Good-day share
Cuyahoga County, Ohio
Median AQI 53 · 43.3% Good-day share
Same primary pollutant: PM2.5
PM2.5 led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Kings County, California
34.5% Good-day share · median AQI 57
Orange County, California
37.8% Good-day share · median AQI 53
St. Louis City County, Missouri
34.3% Good-day share · median AQI 55
Montgomery County, Texas
39.1% Good-day share · median AQI 53
Franklin County, Ohio
40.3% Good-day share · median AQI 53
Tarrant County, Texas
31.8% Good-day share · median AQI 56
Michigan counties on the map
Geographic containment only, other monitored counties in Michigan, independent of AQI or pollutant match.
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 54 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 365 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Wayne County, Michigan? ▼
Wayne County has a median Air Quality Index (AQI) of 54, rated "Moderate." 36.2% of monitored days (132 out of 365) 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 299 days (82% 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 across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2025 at 36.2% (132 of 365 days). Lowest qualifying Good-day share: 2022 at 17.3% (63 of 365 days).
What does AQI 54 mean for health? ▼
Wayne County's median AQI of 54 falls in the "Moderate" category. See the AQI category guide for what each range means for health.
How does Wayne County compare to other counties in Michigan? ▼
Wayne County has 36.2% good air days. Nearby counties in Michigan: Allegan (63.9% good), Bay (70.4% 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 75, 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. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Wayne County, Michigan · 2020–2025
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Every figure on PlainAirData 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.