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 6 Nov 2025: Cholula 31.9 µg/m³, San Francisco Tlalcilalcalpan 28.1 µg/m³ and Santiaguito Tlalcilalcalli 28.1 µg/m³.
- 1CholulaPuebla31.9
- 2San Francisco TlalcilalcalpanMéxico28.1
- 3Santiaguito TlalcilalcalliMéxico28.1
- 4TijuanaBaja California27.6
- 5XonacatlánMéxico27.5
- 6San Antonio la IslaMéxico26.5
- 7San Salvador TizatlalliMéxico26.5
- 8Hacienda Santa FeJalisco24.6
- 9TuxtlaChiapas22.5
- 10Ciudad Benito JuárezNuevo León21.4
- 11TlaquepaqueJalisco21.3
- 12Santa CatarinaNuevo León20.8
- 13GarcíaNuevo León20.6
- 14SalamancaGuanajuato19.4
- 15SaltilloCoahuila19.1
- 16MexicaliBaja California18.3
- 17Naucalpan de JuárezMéxico17.2
- 18Santa AnitaJalisco16.8
- 19MoreliaMichoacán16.7
- 20PueblaPuebla16.4
+ 27 more cities, 16.3 µg/m³ and below
Not counted on this day, too few days measured: Irapuato since 5 Nov 2025, San Miguel de Allende since 1 Nov 2025, San Luis Potosí since 30 Oct 2025 and 3 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.