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 7 Sep 2025: Cholula 27.2 µg/m³, Xonacatlán 24.6 µg/m³ and Tuxtla 23.9 µg/m³.
- 1CholulaPuebla27.2
- 2XonacatlánMéxico24.6
- 3TuxtlaChiapas23.9
- 4San Antonio la IslaMéxico22.0
- 5San Salvador TizatlalliMéxico22.0
- 6Naucalpan de JuárezMéxico18.0
- 7TijuanaBaja California17.2
- 8Ciudad General EscobedoNuevo León16.3
- 9GarcíaNuevo León15.9
- 10Ciudad Benito JuárezNuevo León15.5
- 11MonterreyNuevo León14.9
- 12Mexico CityMexico City14.4
- 13PueblaPuebla13.8
- 14MoreliaMichoacán13.5
- 15San MarcosHidalgo13.2
- 16Santa AnitaJalisco13.0
- 17MexicaliBaja California12.9
- 18TlaquepaqueJalisco12.7
- 19San Martin Texmelucan de LabastidaPuebla12.3
- 20MéridaYucatán12.2
+ 17 more cities, 12.1 µg/m³ and below
Not counted on this day, too few days measured: Tepeji del Río de Ocampo since 7 Sep 2025, San Francisco Tlalcilalcalpan since 7 Sep 2025, Santiaguito Tlalcilalcalli since 7 Sep 2025 and 16 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.