SmogRank / World / North America / United States / Utah

Most polluted cities in Utah, United States

20 measured cities, last 30 days; 0 above the WHO 24-hour guideline. Worst: Millcreek at 7.1 µg/m³, #1,286 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.

Idaho: 12 measured citiesArizona: 16 measured citiesCalifornia: 123 measured citiesNew Mexico: 8 measured citiesUtah: 20 measured citiesWyoming: 10 measured citiesNevada: 11 measured citiesColorado: 19 measured cities#20 Price: 3.1 µg/m³#19 Vernal: 3.2 µg/m³#17 Hurricane: 3.9 µg/m³#18 Heber City: 3.9 µg/m³#16 Moab: 4.1 µg/m³#14 North Ogden: 4.4 µg/m³#15 Roosevelt: 4.4 µg/m³#13 Enoch: 4.9 µg/m³#11 Brigham City: 5.0 µg/m³#12 Orem: 5.0 µg/m³#10 Herriman: 5.1 µg/m³#6 Bountiful: 5.4 µg/m³#7 Magna: 5.4 µg/m³#8 Spanish Fork: 5.4 µg/m³#9 Stansbury park: 5.4 µg/m³#5 Salt Lake City: 5.8 µg/m³#4 West Jordan: 6.1 µg/m³#3 West Valley City: 6.4 µg/m³#2 Smithfield: 6.5 µg/m³#1 Millcreek: 7.1 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Millcreek 0% 0.75%0
Every measured city in Utah, 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. 1Millcreek 0%
  2. 2Smithfield 0%
  3. 3West Valley City 0%
  4. 4West Jordan 0%
  5. 5Salt Lake City 0%
  6. 6Bountiful 0%
  7. 6Magna 0%
  8. 6Spanish Fork 0%
  9. 6Stansbury park 0%
  10. 10Herriman 0%
  11. 11Brigham City 0%
  12. 11Orem 0%
  13. 13Enoch 0%
  14. 14North Ogden 0%
  15. 14Rooseveltlast full day 3 Oct 0%
  16. 16Moab 0%
  17. 17Hurricane 0%
  18. 17Heber City 0%
  19. 19Vernal 0%
  20. 20Price 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

Utah 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
Provo≈ 4 µg/m³Good
Sandy≈ 9 µg/m³Moderate
Ogden≈ 5 µg/m³Good
Layton≈ 5 µg/m³Good
Saint George≈ 2 µg/m³Good
South Jordan≈ 9 µg/m³Moderate
Taylorsville≈ 7 µg/m³Good
Lehi≈ 9 µg/m³Moderate
Logan≈ 4 µg/m³Good
Murray≈ 7 µg/m³Good
Draper≈ 9 µg/m³Moderate
Riverton≈ 9 µg/m³Moderate
Pleasant Grove≈ 4 µg/m³Good
Roy≈ 5 µg/m³Good
Kearns≈ 7 µg/m³Good
Cottonwood Heights≈ 7 µg/m³Good
Tooele≈ 11 µg/m³Moderate
Midvale≈ 7 µg/m³Good
Springville≈ 5 µg/m³Good
Holladay≈ 7 µg/m³Good
Clearfield≈ 5 µg/m³Good
Kaysville≈ 5 µg/m³Good
Cedar City≈ 2 µg/m³Good
American Fork≈ 4 µg/m³Good
Syracuse≈ 5 µg/m³Good
Eagle Mountain≈ 9 µg/m³Moderate
Saratoga Springs≈ 9 µg/m³Moderate
South Salt Lake≈ 7 µg/m³Good
Washington≈ 2 µg/m³Good
Farmington≈ 7 µg/m³Good
Clinton≈ 5 µg/m³Good
East Millcreek≈ 7 µg/m³Good
North Salt Lake≈ 7 µg/m³Good
Payson≈ 5 µg/m³Good
Highland≈ 4 µg/m³Good
South Ogden≈ 5 µg/m³Good
Centerville≈ 7 µg/m³Good

Bad-air episodes in Utah

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 Utah, United States, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/us/region/utah?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.