Air quality · Michigan
Air quality in Michigan
Across the 6 Michigan ZIPs with EPA county air-quality data, the median day ranges from Good to Moderate (median AQI 38–54). 11 days across those counties reached Unhealthy or worse in 2025. This is a 2025 county annual summary, not a live reading.
Last verified 2026-09-24 · methodology
Air quality by ZIP code in Michigan
EPA's 2025 annual summary for each ZIP's county. Median AQI is the typical day; lower is cleaner.
| ZIP | Median AQI | Good days | Unhealthy or worse |
|---|---|---|---|
| 48201DetroitWayne County | 54 Moderate | 132 of 365 | 3 |
| 48226Detroit (Downtown)Wayne County | 54 Moderate | 132 of 365 | 3 |
| 48933LansingIngham County | 38 Good | 265 of 365 | 1 |
| 49503Grand RapidsKent County | 52 Moderate | 153 of 365 | 2 |
| 48104Ann ArborWashtenaw County | 41 Good | 253 of 365 | 1 |
| 48823East LansingIngham County | 38 Good | 265 of 365 | 1 |
County-level figures from EPA Air Quality System (AQS), annual county summary, joined to each ZIP by county. None of them is a measurement at a specific address.
What lands here
Pages show the 2025 median AQI category (Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, Hazardous) for the ZIP's county, plus the year's max/90th-percentile AQI and day-count breakdown by category.
Source & refresh
EPA Air Quality System (AQS), annual county summary. Refreshed annual (epa aqs publication). Primary source →
Michigan top concern
Lead pipes (post-Flint), Great Lakes erosion
Michigan's LCRR obligations are among the heaviest in the US — Detroit, Flint, Benton Harbor, Lansing all carry significant lead-service-line replacement commitments. Great Lakes shoreline erosion expands FEMA AE zones in some lakefront counties.
See Michigan state page for the full state-level rollup across all 12 dimensions.
Read more on air quality
Editorial deep-dives explaining the source data, its limits, and how to read it.
EPA AQI categories explained — what 0–50 Good through 301–500 Hazardous mean
Plain-English guide to the six EPA Air Quality Index categories: 0–50 Good, 51–100 Moderate, 101–150 Unhealthy for Sensitive Groups, 151–200 Unhealthy, 201–300 Very Unhealthy, 301–500 Hazardous — what each level means and who is at risk.
AQI explained — what 50, 100, 150 actually mean for your lungs
Plain-English guide to the EPA Air Quality Index (AQI) and the 6 categories from Good to Hazardous. When to take precautions and which pollutants matter.
Wildfire Hazard Potential — what the USFS scale means and how to defend your home
Plain-English guide to the USDA Forest Service's Wildfire Hazard Potential 1–5 scale, how to read your community's risk, and concrete home-defense measures.
AirNow + wildfire smoke — when AQI is a real-time tool
How EPA AirNow handles real-time wildfire smoke, what the colors mean during fire season, and where AirNow leaves gaps you should know about.