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 13 Jul 2025: Cholula 35.5 µg/m³, Tepeji del Río de Ocampo 19.0 µg/m³ and Atotonilco de Tula 18.7 µg/m³.
- 1CholulaPuebla35.5
- 2Tepeji del Río de OcampoHidalgo19.0
- 3Atotonilco de TulaHidalgo18.7
- 4MexicaliBaja California17.3
- 5ApizacoTlaxcala15.5
- 6La Providencia Siglo XXIHidalgo15.4
- 7TijuanaBaja California15.3
- 8Ciudad JuárezChihuahua14.9
- 9Santa CatarinaNuevo León14.7
- 10Ciudad Benito JuárezNuevo León14.6
- 11SaltilloCoahuila14.5
- 12TlaquepaqueJalisco12.9
- 13MonterreyNuevo León12.9
- 14AguascalientesAguascalientes12.7
- 15PueblaPuebla12.0
- 16Mexico CityMexico City11.9
- 17San Martin Texmelucan de LabastidaPuebla11.6
- 18Mixquiahuala de JuárezHidalgo11.0
- 19TulancingoHidalgo10.2
- 20Heroica MatamorosTamaulipas9.9
+ 11 more cities, 9.9 µg/m³ and below
Not counted on this day, too few days measured: García since 13 Jul 2025, Victoria de Durango since 11 Jul 2025, Atlixco since 9 Jul 2025 and 18 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.