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 14 Jan 2025: Tijuana 31.5 µg/m³, Ciudad Nezahualcoyotl 30.3 µg/m³ and Nogales 26.4 µg/m³.
- 1TijuanaBaja California31.5
- 2Ciudad NezahualcoyotlMéxico30.3
- 3NogalesSonora26.4
- 4IrapuatoGuanajuato25.2
- 5Silao de la VictoriaGuanajuato25.0
- 6León de los AldamaGuanajuato21.7
- 7Mexico CityMexico City20.1
- 8San Luis de la PazGuanajuato18.5
- 9CelayaGuanajuato17.4
- 10AbasoloGuanajuato15.8
- 11SalamancaGuanajuato15.3
- 12San Miguel de AllendeGuanajuato13.6
- 13GuanajuatoGuanajuato13.3
- 14Heroica MatamorosTamaulipas8.7
Not counted on this day, too few days measured: Naucalpan de Juárez since 9 Jan 2025.
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 readers for them. Most cities there are missing from this board, not clean. Why.