SmogRank / World / North America / United States / Iowa

Most polluted cities in Iowa, United States

9 measured cities, last 30 days; 0 above the WHO 24-hour guideline. Worst: Waterloo at 6.5 µg/m³, #1,555 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 citiesSouth Dakota: 7 measured citiesNebraska: 6 measured citiesKansas: 7 measured citiesIowa: 9 measured citiesMissouri: 10 measured citiesWisconsin: 9 measured citiesIllinois: 37 measured cities#9 Des Moines: 4.5 µg/m³#8 Fort Dodge: 5.0 µg/m³#4 Ankeny: 5.1 µg/m³#5 Davenport: 5.1 µg/m³#6 Iowa City: 5.1 µg/m³#7 Muscatine: 5.1 µg/m³#2 Cedar Rapids: 5.3 µg/m³#3 Clinton: 5.3 µg/m³#1 Waterloo: 6.5 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Waterloo 0% 0.75%0
Every measured city in Iowa, 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. 1Waterloo 0%
  2. 2Cedar Rapids 0%
  3. 2Clinton 0%
  4. 4Ankeny 0%
  5. 4Davenport 0%
  6. 4Iowa City 0%
  7. 4Muscatine 0%
  8. 8Fort Dodge 0%
  9. 9Des Moines 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

Iowa 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
Sioux City≈ 6 µg/m³Good
Ames≈ 5 µg/m³Good
West Des Moines≈ 7 µg/m³Good
Council Bluffs≈ 6 µg/m³Good
Dubuque≈ 5 µg/m³Good
Urbandale≈ 7 µg/m³Good
Cedar Falls≈ 5 µg/m³Good
Marion≈ 5 µg/m³Good
Bettendorf≈ 7 µg/m³Good
Marshalltown≈ 5 µg/m³Good
Mason City≈ 4 µg/m³Good
Burlington≈ 5 µg/m³Good
Ottumwa≈ 5 µg/m³Good
Johnston≈ 7 µg/m³Good
Coralville≈ 6 µg/m³Good
Waukee≈ 5 µg/m³Good
Altoona≈ 7 µg/m³Good
North Liberty≈ 6 µg/m³Good
Indianola≈ 5 µg/m³Good
Clive≈ 7 µg/m³Good
Newton≈ 6 µg/m³Good

Bad-air episodes in Iowa

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 Iowa, United States, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/us/region/iowa?w=30d.

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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.