SmogRank / Countries / United States / Wyoming

Most polluted cities in Wyoming, United States

6 measured cities, this year; 1 above the WHO annual guideline. Worst: Sheridan at 6.6 µg/m³, #1,861 in the world.

6 good

  1. 1Sheridan 6.61.3×
  2. 2Gillette 4.30.9×
  3. 3Rock Springs 3.50.7×
  4. 4Laramie 3.30.7×
  5. 5Cheyenne 3.20.6×
  6. 6Casper 3.10.6×
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Updated 2026-10-01 23:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.