SmogRank / History / City race

Cities in Mexico, worst air first, day by day

Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.

CountriesCities
The 30 days to22 Oct 2023 That day's board

The worst cities in Mexico for PM2.5 over the 30 days to 22 Oct 2023: Mexicali 26.6 µg/m³, Tijuana 24.9 µg/m³ and San Francisco Tlalcilalcalpan 22.2 µg/m³.

  1. 1MexicaliBaja California26.6
  2. 2TijuanaBaja California24.9
  3. 3San Francisco TlalcilalcalpanMéxico22.2
  4. 4Santiaguito TlalcilalcalliMéxico22.2
  5. 5TolucaMéxico21.2
  6. 6CholulaPuebla18.3
  7. 7Atotonilco de TulaHidalgo18.3
  8. 8SalamancaGuanajuato18.2
  9. 9CuernavacaMorelos17.3
  10. 10Santa CatarinaNuevo León17.3
  11. 11Ciudad ApodacaNuevo León17.1
  12. 12Ciudad Benito JuárezNuevo León15.1
  13. 13MoreliaMichoacán14.9
  14. 14CelayaGuanajuato14.2
  15. 15PueblaPuebla13.1
  16. 16NogalesSonora13.0
  17. 17Ciudad JuárezChihuahua13.0
  18. 18MonterreyNuevo León12.5
  19. 19León de los AldamaGuanajuato10.8
  20. 20San Andrés TuxtlaVeracruz10.0

+ 4 more cities, 10.0 µg/m³ and below

Not counted on this day, too few days measured: San Marcos since 21 Oct 2023, Pachuca de Soto since 21 Oct 2023, Ciudad General Escobedo since 21 Oct 2023 and 21 more cities.

30 days7 days
GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that day

A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.

Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.