SmogRank / Countries / United States / Idaho
Most polluted cities in Idaho, United States
8 measured cities ranked by PM2.5, this year. Worst: Nampa at 12.8 µg/m³, #392 in the world.
| # | City | µg/m³ | |
|---|---|---|---|
| 1 | Nampa Idaho | 12.8 | |
| 2 | Lewiston Idaho | 10.0 | |
| 3 | Boise Idaho | 8.9 | |
| 4 | Coeur d'Alene Idaho | 8.7 | |
| 5 | Twin Falls Idaho | 7.5 | |
| 6 | Moscow Idaho | 6.4 | |
| 7 | Pocatello Idaho | 6.2 | |
| 8 | Idaho Falls Idaho | 5.4 |
Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data
Estimated: cities without a monitor
Idaho 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 |
|---|---|
| Caldwell estimated | ≈ 6 µg/m³ |
| Lewiston Orchards estimated | ≈ 4 µg/m³ |
| Post Falls estimated | ≈ 4 µg/m³ |
| Eagle Foothills estimated | ≈ 6 µg/m³ |
| Rexburg estimated | ≈ 4 µg/m³ |
| Eagle estimated | ≈ 6 µg/m³ |
| Conda estimated | ≈ 2 µg/m³ |
| Kuna estimated | ≈ 6 µg/m³ |
Updated 2026-10-01 10:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.