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 worst cities in Mexico for PM2.5 over the 30 days to 17 Jan 2025: Tijuana 30.8 µg/m³, Ciudad Nezahualcoyotl 29.9 µg/m³ and Naucalpan de Juárez 27.9 µg/m³.
- 1TijuanaBaja California30.8
- 2Ciudad NezahualcoyotlMéxico29.9
- 3Naucalpan de JuárezMéxico27.9
- 4Silao de la VictoriaGuanajuato25.6
- 5IrapuatoGuanajuato25.6
- 6NogalesSonora24.9
- 7León de los AldamaGuanajuato22.1
- 8Mexico CityMexico City20.3
- 9San Luis de la PazGuanajuato18.5
- 10CelayaGuanajuato17.8
- 11AbasoloGuanajuato16.0
- 12SalamancaGuanajuato15.7
- 13San Miguel de AllendeGuanajuato14.1
- 14GuanajuatoGuanajuato13.8
- 15Heroica MatamorosTamaulipas9.0
Cities counted each 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.