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 9 Feb 2025: Xonacatlán 31.0 µg/m³, Silao de la Victoria 24.4 µg/m³ and Irapuato 23.3 µg/m³.
- 1XonacatlánMéxico31.0
- 2Silao de la VictoriaGuanajuato24.4
- 3IrapuatoGuanajuato23.3
- 4Ciudad NezahualcoyotlMéxico22.5
- 5Mexico CityMexico City20.7
- 6San Luis de la PazGuanajuato18.0
- 7TijuanaBaja California17.2
- 8NogalesSonora17.1
- 9CelayaGuanajuato16.5
- 10AbasoloGuanajuato15.9
- 11SalamancaGuanajuato15.5
- 12GuanajuatoGuanajuato13.0
- 13San Miguel de AllendeGuanajuato12.1
- 14Heroica MatamorosTamaulipas7.8
Not counted on this day, too few days measured: Ecatepec de Morelos since 6 Feb 2025, Naucalpan de Juárez since 31 Jan 2025 and León de los Aldama since 20 Jan 2025.
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.