Air quality · Wisconsin
Air quality in Wisconsin
Across the 3 Wisconsin ZIPs with EPA county air-quality data, the median day is Good in all 3 (median AQI 41–43). 4 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 Wisconsin
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 |
|---|---|---|---|
| 53202MilwaukeeMilwaukee County | 43 Good | 228 of 365 | 2 |
| 53703MadisonDane County | 41 Good | 246 of 365 | 1 |
| 54481Stevens PointPortage County | No data | ||
| 53715Madison (campus)Dane County | 41 Good | 246 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 →
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