SmogRank / World / North America

Most polluted cities in North America

11 of 828 measured cities in 6 countries were above the WHO 24-hour guideline over the last 30 days. The worst was Tuxtla, Mexico, at 29.1 µg/m³.

VenezuelaU.S. Virgin IslandsPuerto Rico: 1 measured cityUnited States: 690 measured citiesAnguillaCayman IslandsBermudaBritish Virgin IslandsTurks and Caicos IslandsTrinidad and TobagoSurinameSaint Vincent and the GrenadinesSaint LuciaSaint Kitts and NevisRussiaPanamaNicaraguaArubaCuracaoMexico: 40 measured citiesJamaicaHonduras: 1 measured cityHaitiGuyanaGuatemalaGrenadaFrance: 102 measured citiesSaint Pierre and MiquelonSaint Martin: 1 measured cityEl SalvadorDominican RepublicDominicaGreenlandCubaCosta RicaColombiaCanada: 95 measured citiesBrazil: 6 measured citiesBelizeBarbadosBahamasAntigua and BarbudaSint Maarten
Each dot is a measured city, coloured by its PM2.5 over the last 30 days; tap a country to open it.
← Tuxtla 29.1 WHO 24-hour guideline
Every measured city in North America, one column each, worst on the left and cleanest on the right. Point at it to read a city; tap to open it.

Countries

CountryCitiesMedianCities by bandWorst city
Mexico4012.7 Tuxtla 29.1
Honduras112.6 San Pedro Sula 12.6
Puerto Rico110.3 Cataño 10.3
Saint Martin19.1 Marigot 9.1
United States6905.7 Calexico 23.0
Canada955.0 Kamloops 8.4

Worst cities

  1. 1TuxtlaChiapas, Mexico 88
  2. 2Hacienda Santa FeJalisco, Mexico 79
  3. 3CalexicoCalifornia, United States 77
  4. 4San Salvador TizatlalliMéxico, Mexico 69
  5. 5Ciudad NezahualcoyotlMéxico, Mexico 68
  6. 6Naucalpan de JuárezMéxico, Mexico 67
  7. 7Santa AnitaJalisco, Mexico 67
  8. 8AguascalientesAguascalientes, Mexico 67
  9. 9GuadalajaraJalisco, Mexico 67
  10. 10SaltilloCoahuila, Mexico 66
  11. 11PueblaPuebla, Mexico 63
  12. 12Parque Industrial Ciudad MitrasNuevo León, Mexico 62
  13. 13Ciudad General EscobedoNuevo León, Mexico 61
  14. 14Mexico CityMexico City, Mexico 61
  15. 15TlaquepaqueJalisco, Mexico 61
  16. 16CelayaGuanajuato, Mexico 60
  17. 17SalamancaGuanajuato, Mexico 60
  18. 18León de los AldamaGuanajuato, Mexico 59
  19. 19IrapuatoGuanajuato, Mexico 58
  20. 20MonterreyNuevo León, Mexico 58
  21. 21Jurupa ValleyCalifornia, United States 58
  22. 22TijuanaBaja California, Mexico 58
  23. 23San Pedro Sulalow-cost sensorsCortés Department, Honduras 58
  24. 24Santa CatarinaNuevo León, Mexico 57
  25. 25RiversideCalifornia, United States 57
All cities in the world
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

Updated 2026-10-02 05:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.