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 Dec 2025: Hacienda Santa Fe 41.9 µg/m³, Aguascalientes 38.9 µg/m³ and Tlaquepaque 35.8 µg/m³.
- 1Hacienda Santa FeJalisco41.9
- 2AguascalientesAguascalientes38.9
- 3TlaquepaqueJalisco35.8
- 4XonacatlánMéxico35.0
- 5TijuanaBaja California34.2
- 6San Antonio la IslaMéxico33.4
- 7San Salvador TizatlalliMéxico33.4
- 8GuadalajaraJalisco33.3
- 9San Francisco TlalcilalcalpanMéxico32.1
- 10Santiaguito TlalcilalcalliMéxico32.1
- 11Ciudad NezahualcoyotlMéxico30.2
- 12Ciudad Benito JuárezNuevo León28.2
- 13Santa CatarinaNuevo León27.4
- 14Zacatepec de HidalgoMorelos26.6
- 15AtlixcoPuebla26.3
- 16MexicaliBaja California26.2
- 17IrapuatoGuanajuato24.9
- 18Ciudad General EscobedoNuevo León24.1
- 19PueblaPuebla24.0
- 20Naucalpan de JuárezMéxico23.1
+ 28 more cities, 22.9 µg/m³ and below
Not counted on this day, too few days measured: García since 2 Dec 2025, San Marcos since 1 Dec 2025, Cholula since 1 Dec 2025 and 7 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.