SmogRank / World / North America

Most polluted cities in North America

8 of 828 measured cities in 6 countries were above the WHO 24-hour guideline over the last 7 days. The worst was Calexico, United States, at 29.5 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: 42 measured citiesJamaicaHonduras: 1 measured cityHaitiGuyanaGuatemalaGrenadaFrance: 94 measured citiesSaint Pierre and MiquelonSaint Martin: 1 measured cityEl SalvadorDominican RepublicDominicaGreenlandCubaCosta RicaColombiaCanada: 93 measured citiesBrazil: 6 measured citiesBelizeBarbadosBahamasAntigua and BarbudaSint Maarten
Each dot is a measured city, coloured by its PM2.5 over the last 7 days; tap a country to open it.
← Calexico 29.5 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
Honduras119.4 San Pedro Sula 19.4
Mexico429.5 Hacienda Santa Fe 22.8
Puerto Rico18.6 Cataño 8.6
Saint Martin16.6 Marigot 6.6
United States6905.4 Calexico 29.5
Canada934.9 Calgary 7.0

Worst cities

  1. 1CalexicoCalifornia, United States 43
  2. 2Hacienda Santa FeJalisco, Mexico 33
  3. 3San Pedro Sulalow-cost sensorsCortés Department, Honduras 28
  4. 4San Salvador TizatlalliMéxico, Mexico 25
  5. 5TijuanaBaja California, Mexico 24
  6. 6Santa AnitaJalisco, Mexico 23
  7. 7AguascalientesAguascalientes, Mexico 23
  8. 8GuadalajaraJalisco, Mexico 23
  9. 9TlaquepaqueJalisco, Mexico 22
  10. 10Naucalpan de JuárezMéxico, Mexico 21
  11. 11Los AngelesCalifornia, United States 21
  12. 12Jurupa ValleyCalifornia, United States 21
  13. 13RichmondCalifornia, United States 20
  14. 14ClovisCalifornia, United States 20
  15. 15TepicNayarit, Mexico 19
  16. 16RiversideCalifornia, United States 19
  17. 17Little RockArkansas, United States 19
  18. 18HanfordCalifornia, United States 19
  19. 19FontanaCalifornia, United States 19
  20. 20MexicaliBaja California, Mexico 18
  21. 21WhittierCalifornia, United States 18
  22. 22PueblaPuebla, Mexico 18
  23. 23Chula VistaCalifornia, United States 18
  24. 24San DiegoCalifornia, United States 18
  25. 25Lawrencelow-cost sensorsKansas, 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 03:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the China AQI PM2.5 sub-index.