SmogRank / World / North America / United States / Iowa
Most polluted cities in Iowa, United States
9 measured cities, this year; 9 above the WHO annual guideline. Worst: Waterloo at 9.4 µg/m³, #1,168 in the world.
About 1.64K people in these 2 cities breathed unhealthy air on an average day so far this year.
Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.
Cities coloured by their PM2.5 over the last 24 hours. Fires, smoke and ash: Oct 5, the newest UTC day mapped.
- 1Des Moines 1.54K
- 2Clinton 94
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.
| City | 7-day estimate |
|---|---|
| Sioux City | ≈ 6 µg/m³ |
| Ames | ≈ 5 µg/m³ |
| West Des Moines | ≈ 7 µg/m³ |
| Council Bluffs | ≈ 6 µg/m³ |
| Dubuque | ≈ 5 µg/m³ |
| Urbandale | ≈ 7 µg/m³ |
| Cedar Falls | ≈ 5 µg/m³ |
| Marion | ≈ 5 µg/m³ |
| Bettendorf | ≈ 7 µg/m³ |
| Marshalltown | ≈ 5 µg/m³ |
| Mason City | ≈ 4 µg/m³ |
| Burlington | ≈ 5 µg/m³ |
| Ottumwa | ≈ 5 µg/m³ |
| Johnston | ≈ 7 µg/m³ |
| Coralville | ≈ 6 µg/m³ |
| Waukee | ≈ 5 µg/m³ |
| Altoona | ≈ 7 µg/m³ |
| North Liberty | ≈ 6 µg/m³ |
| Indianola | ≈ 5 µg/m³ |
| Clive | ≈ 7 µg/m³ |
| Newton | ≈ 6 µg/m³ |
Bad-air episodes in Iowa
- Northern United States and Canada, July 202614 to 21 July 2026, 8 days327 cities548 µg/m³peak, Superior
- Northern United States, July 20264 to 5 July 2026, 2 days10 cities85 µg/m³peak, Omaha
- North-eastern United States and Canada, March 20264 to 5 March 2026, 2 days40 cities38 µg/m³peak, Hamilton
- North-eastern United States and Canada, 14 to 19 February 20266 days108 cities54 µg/m³peak, Lancaster
- Northern United States, December 202524 to 25 December 2025, 2 days11 cities33 µg/m³peak, Wheaton
- North-eastern United States and Canada, 29 July to 9 August 202512 days292 cities112 µg/m³peak, Marquette
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, this year to 6 Oct 2026, 23:00 UTC, smogrank.com/us/region/iowa?w=year.
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 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.