SmogRank / World / Mexico / September 2025

Most unhealthy days in Mexico, September 2025

42 cities in Mexico ranked by their share of unhealthy days over the 30 days. The most unhealthy days: Cholula, Mexico, 6 of 29 measured days. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Cholula 21% 20%0
Every city in Mexico ranked for September 2025, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1CholulaPuebla
    6 of 29
  2. 2Santa AnitaJalisco
    1 of 21
  3. 3Santa CatarinaNuevo León
    1 of 25
  4. 4San Antonio la IslaMéxico
    1 of 28
  5. 5XonacatlánMéxico
    0 of 30
  6. 6CuernavacaMorelos
    0 of 26
  7. 7TijuanaBaja California
    0 of 29
  8. 8Atotonilco de TulaHidalgo
    0 of 26
  9. 9GarcíaNuevo León
    0 of 27
  10. 10Naucalpan de JuárezMéxico
    0 of 26
  11. 11PueblaPuebla
    0 of 30
  12. 12La PazBaja California Sur
    0 of 22
  13. 12Ciudad Benito JuárezNuevo León
    0 of 30
  14. 14Ciudad General EscobedoNuevo León
    0 of 25
  15. 15Mexico CityMexico City
    0 of 26
  16. 16San MarcosHidalgo
    0 of 23
  17. 17SalamancaGuanajuato
    0 of 29
  18. 18ZapopanJalisco
    0 of 30
  19. 19MonterreyNuevo León
    0 of 30
  20. 20San Luis de la PazGuanajuato
    0 of 23
  21. 21MéridaYucatán
    0 of 24
  22. 21León de los AldamaGuanajuato
    0 of 29
  23. 23TlaquepaqueJalisco
    0 of 30
  24. 24San Martin Texmelucan de LabastidaPuebla
    0 of 25
  25. 25TulancingoHidalgo
    0 of 30
  26. 26Mixquiahuala de JuárezHidalgo
    0 of 30
  27. 26AguascalientesAguascalientes
    0 of 30
  28. 28CelayaGuanajuato
    0 of 27
  29. 29San Miguel de AllendeGuanajuato
    0 of 27
  30. 29Ciudad JuárezChihuahua
    0 of 30
  31. 31TehuacánPuebla
    0 of 30
  32. 32Zacatepec de HidalgoMorelos
    0 of 30
  33. 33TepicNayarit
    0 of 30
  34. 34Santiago de QuerétaroQuerétaro
    0 of 30
  35. 34NogalesSonora
    0 of 29
  36. 36San Juan del RíoQuerétaro
    0 of 30
  37. 37IrapuatoGuanajuato
    0 of 24
  38. 38HuichapanHidalgo
    0 of 28
  39. 39AbasoloGuanajuato
    0 of 27
  40. 40La Providencia Siglo XXIHidalgo
    0 of 29
  41. 41Heroica MatamorosTamaulipas
    0 of 28
  42. 42Pachuca de SotoHidalgo
    0 of 29
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, September 2025 · Mexico now

Regions

Aguascalientes 1Baja California 1Baja California Sur 1Chihuahua 1Guanajuato 7Hidalgo 7Jalisco 3México 3Mexico City 1Morelos 2Nayarit 1Nuevo León 5Puebla 4Querétaro 2Sonora 1Tamaulipas 1Yucatán 1

Ranked cities in each region, September 2025.

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SmogRank, most polluted cities in Mexico, by unhealthy days, PM2.5, September 2025, smogrank.com/mx/history/2025-09?by=days (accessed 7 Oct 2026).

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