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 to9 Sep 2026 That day's board

The worst cities in Mexico for PM2.5 over the 30 days to 9 Sep 2026: Mexicali 29.7 µg/m³, San Luis Potosí 28.4 µg/m³ and Tuxtla 28.0 µg/m³.

  1. 1MexicaliBaja California29.7
  2. 2San Luis PotosíSan Luis Potosí28.4
  3. 3TuxtlaChiapas28.0
  4. 4Hacienda Santa FeJalisco25.6
  5. 5TijuanaBaja California23.5
  6. 6San Antonio la IslaMéxico22.3
  7. 7San Salvador TizatlalliMéxico22.3
  8. 8MéridaYucatán22.2
  9. 9Parque Industrial Ciudad MitrasNuevo León21.2
  10. 10Santa AnitaJalisco20.7
  11. 11Ciudad NezahualcoyotlMéxico20.5
  12. 12Naucalpan de JuárezMéxico20.2
  13. 13AtlixcoPuebla19.9
  14. 14Ciudad General EscobedoNuevo León18.6
  15. 15GuadalajaraJalisco18.3
  16. 16AguascalientesAguascalientes18.3
  17. 17Silao de la VictoriaGuanajuato17.7
  18. 18Santa CatarinaNuevo León17.7
  19. 19PueblaPuebla17.5
  20. 20SalamancaGuanajuato17.1

+ 30 more cities, 16.8 µg/m³ and below

Not counted on this day, too few days measured: Cuernavaca since 4 Sep 2026, Tlaxcala since 16 Aug 2026, San Marcos since 8 Aug 2026 and La Paz since 12 Jul 2026.

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.