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 21 May 2023: Celaya 39.6 µg/m³, Salamanca 29.2 µg/m³ and Silao de la Victoria 27.9 µg/m³.
- 1CelayaGuanajuato39.6
- 2SalamancaGuanajuato29.2
- 3Silao de la VictoriaGuanajuato27.9
- 4León de los AldamaGuanajuato27.0
- 5Naucalpan de JuárezMéxico24.4
- 6Mexico CityMexico City24.1
- 7GuanajuatoGuanajuato22.6
- 8Ciudad JuárezChihuahua22.5
- 9AbasoloGuanajuato22.1
- 10IrapuatoGuanajuato21.9
- 11San Miguel de AllendeGuanajuato19.6
- 12San Luis de la PazGuanajuato18.9
- 13NogalesSonora9.2
Not counted on this day, too few days measured: Tijuana since 19 May 2023, Cuernavaca since 12 May 2023, Atotonilco de Tula since 12 May 2023 and 30 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.
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.