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 to7 Aug 2026 That day's board

The worst cities in Mexico for PM2.5 over the 30 days to 7 Aug 2026: San Luis Potosí 27.8 µg/m³, Tuxtla 26.3 µg/m³ and Ciudad General Escobedo 22.8 µg/m³.

  1. 1San Luis PotosíSan Luis Potosí27.8
  2. 2TuxtlaChiapas26.3
  3. 3Ciudad General EscobedoNuevo León22.8
  4. 4Atotonilco de TulaHidalgo22.5
  5. 5Naucalpan de JuárezMéxico20.8
  6. 6Santa CatarinaNuevo León20.7
  7. 7MexicaliBaja California20.5
  8. 8TijuanaBaja California20.1
  9. 9Parque Industrial Ciudad MitrasNuevo León20.0
  10. 10Ciudad NezahualcoyotlMéxico19.1
  11. 11PueblaPuebla18.6
  12. 12AguascalientesAguascalientes18.3
  13. 13Silao de la VictoriaGuanajuato18.2
  14. 14MonterreyNuevo León17.3
  15. 15Ciudad ApodacaNuevo León17.3
  16. 16GuadalajaraJalisco17.1
  17. 17SalamancaGuanajuato17.0
  18. 18Mexico CityMexico City16.6
  19. 19Pachuca de SotoHidalgo16.1
  20. 20CelayaGuanajuato16.1

+ 28 more cities, 15.9 µg/m³ and below

Not counted on this day, too few days measured: Hacienda Santa Fe since 21 Jul 2026, La Paz since 12 Jul 2026, Morelia since 4 Jul 2026 and 4 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.