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 15 Aug 2025: San Francisco Tlalcilalcalpan 24.1 µg/m³, Santiaguito Tlalcilalcalli 24.1 µg/m³ and Xonacatlán 23.1 µg/m³.
- 1San Francisco TlalcilalcalpanMéxico24.1
- 2Santiaguito TlalcilalcalliMéxico24.1
- 3XonacatlánMéxico23.1
- 4TuxtlaChiapas22.2
- 5San Antonio la IslaMéxico19.8
- 6San Salvador TizatlalliMéxico19.8
- 7Atotonilco de TulaHidalgo19.3
- 8GarcíaNuevo León18.9
- 9Ciudad Benito JuárezNuevo León17.9
- 10Santa CatarinaNuevo León17.6
- 11Tepeji del Río de OcampoHidalgo17.0
- 12Naucalpan de JuárezMéxico16.4
- 13León de los AldamaGuanajuato15.7
- 14MonterreyNuevo León15.2
- 15MexicaliBaja California15.2
- 16CelayaGuanajuato14.8
- 17Mexico CityMexico City14.2
- 18SalamancaGuanajuato14.2
- 19PueblaPuebla13.2
- 20TijuanaBaja California13.2
+ 22 more cities, 13.1 µg/m³ and below
Not counted on this day, too few days measured: Saltillo since 15 Aug 2025, Apizaco since 14 Aug 2025, Irapuato since 14 Aug 2025 and 14 more cities.
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.