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.

The 30 days to22 Sep 2023 That day's board

The worst cities in Mexico for PM2.5 over the 30 days to 22 Sep 2023: Xonacatlán 30.1 µg/m³, Mexicali 27.8 µg/m³ and San Francisco Tlalcilalcalpan 26.2 µg/m³.

  1. 1XonacatlánMéxico30.1
  2. 2MexicaliBaja California27.8
  3. 3San Francisco TlalcilalcalpanMéxico26.2
  4. 4Santiaguito TlalcilalcalliMéxico26.2
  5. 5San Antonio la IslaMéxico25.6
  6. 6San Salvador TizatlalliMéxico25.6
  7. 7ZapopanJalisco25.2
  8. 8TlaquepaqueJalisco25.2
  9. 9TolucaMéxico24.9
  10. 10CuernavacaMorelos20.8
  11. 11MoreliaMichoacán19.5
  12. 12Ciudad ApodacaNuevo León19.2
  13. 13Ciudad NezahualcoyotlMéxico18.9
  14. 14GuadalajaraJalisco18.5
  15. 15Naucalpan de JuárezMéxico18.0
  16. 16TijuanaBaja California17.7
  17. 17Ciudad JuárezChihuahua17.7
  18. 18Santa CatarinaNuevo León17.1
  19. 19SaltilloCoahuila16.1
  20. 20Tepeji del Río de OcampoHidalgo15.8

+ 23 more cities, 15.5 µg/m³ and below

Not counted on this day, too few days measured: Irapuato since 18 Sep 2023, Cholula since 15 Sep 2023, Victoria de Durango since 13 Sep 2023 and 3 more cities.

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.