SmogRank / World / North America / United States / Wisconsin

Most polluted cities in Wisconsin, United States

9 measured cities, last 30 days; 0 above the WHO 24-hour guideline. Worst: Waukesha at 5.6 µg/m³, #1,955 in the world.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

Minnesota: 16 measured citiesMichigan: 22 measured citiesIowa: 9 measured citiesWisconsin: 9 measured citiesIllinois: 37 measured citiesIndiana: 22 measured cities#9 Baraboo: 3.7 µg/m³#8 Tomah: 4.0 µg/m³#7 Appleton: 4.1 µg/m³#6 Madison: 4.2 µg/m³#5 Superior: 4.4 µg/m³#4 Altoona: 4.8 µg/m³#2 Green Bay: 5.0 µg/m³#3 Greendale: 5.0 µg/m³#1 Waukesha: 5.6 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Waukesha 0% 0.75%0
Every measured city in Wisconsin, United States, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Waukesha 0%
  2. 2Green Bay 0%
  3. 2Greendale 0%
  4. 4Altoonalast full day 3 Oct 0%
  5. 5Superior 0%
  6. 6Madison 0%
  7. 7Appleton 0%
  8. 8Tomah 0%
  9. 9Baraboo 0%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Wisconsin cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Kenosha≈ 6 µg/m³Good
Racine≈ 4 µg/m³Good
Eau Claire≈ 3 µg/m³Good
Oshkosh≈ 4 µg/m³Good
Janesville≈ 4 µg/m³Good
West Allis≈ 5 µg/m³Good
North La Crosse≈ 3 µg/m³Good
Sheboygan≈ 4 µg/m³Good
Wauwatosa≈ 5 µg/m³Good
Fond du Lac≈ 4 µg/m³Good
New Berlin≈ 5 µg/m³Good
Wausau≈ 3 µg/m³Good
Brookfield≈ 5 µg/m³Good
Greenfield≈ 5 µg/m³Good
Beloit≈ 5 µg/m³Good
Franklin≈ 5 µg/m³Good
Menomonee Falls≈ 6 µg/m³Good
Oak Creek≈ 5 µg/m³Good
Manitowoc≈ 4 µg/m³Good
Sun Prairie≈ 5 µg/m³Good
West Bend≈ 4 µg/m³Good
Fitchburg≈ 4 µg/m³Good
Stevens Point≈ 5 µg/m³Good
Mount Pleasant≈ 5 µg/m³Good
Neenah≈ 4 µg/m³Good
Muskego≈ 5 µg/m³Good
De Pere≈ 5 µg/m³Good
Caledonia≈ 5 µg/m³Good
Watertown≈ 4 µg/m³Good
Mequon≈ 6 µg/m³Good
South Milwaukee≈ 5 µg/m³Good
Pleasant Prairie≈ 6 µg/m³Good
Germantown≈ 6 µg/m³Good
Howard≈ 5 µg/m³Good
Middleton≈ 4 µg/m³Good
Marshfield≈ 3 µg/m³Good
Onalaska≈ 3 µg/m³Good
Cudahy≈ 5 µg/m³Good
Wisconsin Rapids≈ 4 µg/m³Good
Menasha≈ 5 µg/m³Good

Bad-air episodes in Wisconsin

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Wisconsin, United States, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/us/region/wisconsin?w=30d.

Download top 10 (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.