SmogRank / World / North America

Most polluted cities in North America

11 of 826 measured cities in 6 countries were above the WHO 24-hour guideline over the last 30 days. The worst was Tuxtla, Mexico, at 28.4 µg/m³.

VenezuelaU.S. Virgin IslandsPuerto Rico: 1 measured cityUnited States: 688 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 28.4 µg/m³ 15 µg/m³ WHO 24-hour guideline0
Every measured city in North America, one column each, worst on the left and cleanest on the right; height is PM2.5 in µg/m³. Point at it to read a city; tap to open it.

Countries

CountryCitiesMedianCities by bandWorst city
Honduras113.2 San Pedro Sula 13.2
Mexico4012.5 Tuxtla 28.4
Puerto Rico110.3 Cataño 10.3
Saint Martin19.1 Marigot 9.1
United States6885.7 Calexico 23.1
Canada955.0 Kamloops 8.1

Worst cities

  1. 1TuxtlaChiapas, Mexico 3
  2. 2Hacienda Santa FeJalisco, Mexico 3
  3. 3CalexicoCalifornia, United States 2
  4. 4San Salvador TizatlalliMéxico, Mexico 2
  5. 5Ciudad NezahualcoyotlMéxico, Mexico 2
  6. 6Naucalpan de JuárezMéxico, Mexico 2
  7. 7Santa AnitaJalisco, Mexico 2
  8. 8AguascalientesAguascalientes, Mexico 2
  9. 9SaltilloCoahuila, Mexico 2
  10. 10GuadalajaraJalisco, Mexico 2
  11. 11PueblaPuebla, Mexico 2
  12. 12Mexico CityMexico City, Mexico 2
  13. 13TlaquepaqueJalisco, Mexico 2
  14. 14Ciudad General EscobedoNuevo León, Mexico 2
  15. 15Parque Industrial Ciudad MitrasNuevo León, Mexico 2
  16. 16SalamancaGuanajuato, Mexico 2
  17. 17CelayaGuanajuato, Mexico 2
  18. 18León de los AldamaGuanajuato, Mexico 2
  19. 19San Pedro Sulalow-cost sensorsCortés Department, Honduras 2
  20. 20Jurupa ValleyCalifornia, United States 2
  21. 21TijuanaBaja California, Mexico 2
  22. 22IrapuatoGuanajuato, Mexico 2
  23. 23MonterreyNuevo León, Mexico 2
  24. 24Santa CatarinaNuevo León, Mexico 2
  25. 25RiversideCalifornia, United States 2
All cities in the world
Low1–3
Moderate4–6
High7–9
Very high10

The UK's Daily Air Quality Index (1 to 10), PM2.5 bands. Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

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