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 30 days to19 May 2024 That day's board

The worst cities in Mexico for PM2.5 over the 30 days to 19 May 2024: Celaya 32.2 µg/m³, San Luis de la Paz 29.1 µg/m³ and León de los Aldama 22.4 µg/m³.

  1. 1CelayaGuanajuato32.2
  2. 2San Luis de la PazGuanajuato29.1
  3. 3León de los AldamaGuanajuato22.4
  4. 4IrapuatoGuanajuato22.3
  5. 5Heroica MatamorosTamaulipas22.2
  6. 6SalamancaGuanajuato21.0
  7. 7San Miguel de AllendeGuanajuato19.7
  8. 8AbasoloGuanajuato17.9
  9. 9NogalesSonora9.4

Not counted on this day, too few days measured: Tlaquepaque since 18 May 2024, Ciudad Juárez since 15 May 2024, Silao de la Victoria since 8 May 2024 and 2 more cities.

GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that 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.