SmogRank / World / North America

Most polluted cities in North America

11 of 831 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: 693 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 Rico110.5 Cataño 10.5
Saint Martin19.3 Marigot 9.3
United States6935.7 Calexico 23.0
Canada955.1 Kamloops 8.4

Worst cities

  1. 1TuxtlaChiapas, Mexico 29.1
  2. 2Hacienda Santa FeJalisco, Mexico 24.0
  3. 3CalexicoCalifornia, United States 23.0
  4. 4San Salvador TizatlalliMéxico, Mexico 19.0
  5. 5Ciudad NezahualcoyotlMéxico, Mexico 18.0
  6. 6Naucalpan de JuárezMéxico, Mexico 17.9
  7. 7Santa AnitaJalisco, Mexico 17.8
  8. 8AguascalientesAguascalientes, Mexico 17.6
  9. 9GuadalajaraJalisco, Mexico 17.5
  10. 10SaltilloCoahuila, Mexico 17.3
  11. 11PueblaPuebla, Mexico 15.3
  12. 12Parque Industrial Ciudad MitrasNuevo León, Mexico 14.9
  13. 13Ciudad General EscobedoNuevo León, Mexico 14.7
  14. 14Mexico CityMexico City, Mexico 14.5
  15. 15TlaquepaqueJalisco, Mexico 14.5
  16. 16CelayaGuanajuato, Mexico 14.1
  17. 17SalamancaGuanajuato, Mexico 13.9
  18. 18León de los AldamaGuanajuato, Mexico 13.4
  19. 19IrapuatoGuanajuato, Mexico 13.0
  20. 20MonterreyNuevo León, Mexico 12.9
  21. 21Jurupa ValleyCalifornia, United States 12.9
  22. 22TijuanaBaja California, Mexico 12.8
  23. 23San Pedro Sulalow-cost sensorsCortés Department, Honduras 12.6
  24. 24Santa CatarinaNuevo León, Mexico 12.5
  25. 25RiversideCalifornia, United States 12.3
All cities in the world
Good0–5
Fair6–15
Moderate16–50
Poor51–90
Very poor91–140
Extremely poor141+

The European Environment Agency's air quality index bands for PM2.5 (2024 revision); it has bands, not numbers, so values stay in µg/m³. Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Updated 2026-10-02 03:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors in µg/m³.