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 Sep 2026: Mexicali 30.0 µg/m³, San Luis Potosí 29.0 µg/m³ and Tuxtla 27.8 µg/m³.
- 1MexicaliBaja California30.0
- 2San Luis PotosíSan Luis Potosí29.0
- 3TuxtlaChiapas27.8
- 4Hacienda Santa FeJalisco26.1
- 5MéridaYucatán22.4
- 6Parque Industrial Ciudad MitrasNuevo León22.0
- 7TijuanaBaja California21.8
- 8Ciudad NezahualcoyotlMéxico20.6
- 9AtlixcoPuebla20.1
- 10Naucalpan de JuárezMéxico19.9
- 11Ciudad General EscobedoNuevo León19.1
- 12AguascalientesAguascalientes18.9
- 13Santa CatarinaNuevo León18.4
- 14GuadalajaraJalisco18.3
- 15Silao de la VictoriaGuanajuato18.0
- 16PueblaPuebla17.8
- 17CelayaGuanajuato17.4
- 18Mexico CityMexico City16.7
- 19SalamancaGuanajuato16.7
- 20MonterreyNuevo León16.0
+ 27 more cities, 15.9 µg/m³ and below
Not counted on this day, too few days measured: Cuernavaca since 4 Sep 2026, Tlaxcala since 16 Aug 2026, San Marcos since 8 Aug 2026 and La Paz since 12 Jul 2026.
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.