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 42
  2. 2Hacienda Santa FeJalisco, Mexico 35
  3. 3CalexicoCalifornia, United States 33
  4. 4San Salvador TizatlalliMéxico, Mexico 28
  5. 5Ciudad NezahualcoyotlMéxico, Mexico 26
  6. 6Naucalpan de JuárezMéxico, Mexico 26
  7. 7Santa AnitaJalisco, Mexico 26
  8. 8AguascalientesAguascalientes, Mexico 26
  9. 9GuadalajaraJalisco, Mexico 25
  10. 10SaltilloCoahuila, Mexico 25
  11. 11PueblaPuebla, Mexico 22
  12. 12Parque Industrial Ciudad MitrasNuevo León, Mexico 22
  13. 13Ciudad General EscobedoNuevo León, Mexico 21
  14. 14Mexico CityMexico City, Mexico 21
  15. 15TlaquepaqueJalisco, Mexico 21
  16. 16CelayaGuanajuato, Mexico 21
  17. 17SalamancaGuanajuato, Mexico 20
  18. 18León de los AldamaGuanajuato, Mexico 20
  19. 19IrapuatoGuanajuato, Mexico 19
  20. 20MonterreyNuevo León, Mexico 19
  21. 21Jurupa ValleyCalifornia, United States 19
  22. 22TijuanaBaja California, Mexico 19
  23. 23San Pedro Sulalow-cost sensorsCortés Department, Honduras 18
  24. 24Santa CatarinaNuevo León, Mexico 18
  25. 25RiversideCalifornia, United States 18
All cities in the world
Excellent0–50
Good51–100
Lightly polluted101–150
Moderately polluted151–200
Heavily polluted201–300
Severely polluted301+

China's Air Quality Index (HJ 633-2012), PM2.5 individual index. 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 China AQI PM2.5 sub-index.