SmogRank / World / Mexico / October 2025

Most unhealthy days in Mexico, October 2025

43 cities in Mexico ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Cholula, Mexico, 6 of 30 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 20% 15%0
Every city in Mexico ranked for October 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 30
  2. 2TijuanaBaja California
    5 of 30
  3. 3NogalesSonora
    3 of 31
  4. 4XonacatlánMéxico
    2 of 31
  5. 5TuxtlaChiapas
    1 of 25
  6. 6SaltilloCoahuila
    1 of 25
  7. 7San Antonio la IslaMéxico
    1 of 29
  8. 8MexicaliBaja California
    1 of 30
  9. 9Santa CatarinaNuevo León
    0 of 28
  10. 10Ciudad Benito JuárezNuevo León
    0 of 30
  11. 11GarcíaNuevo León
    0 of 25
  12. 12Hacienda Santa FeJalisco
    0 of 31
  13. 13Naucalpan de JuárezMéxico
    0 of 24
  14. 14SalamancaGuanajuato
    0 of 26
  15. 15TlaquepaqueJalisco
    0 of 31
  16. 16PueblaPuebla
    0 of 30
  17. 16Mexico CityMexico City
    0 of 31
  18. 18Santa AnitaJalisco
    0 of 31
  19. 19Cadereyta JiménezNuevo León
    0 of 29
  20. 20PesqueríaNuevo León
    0 of 29
  21. 20León de los AldamaGuanajuato
    0 of 25
  22. 22Mixquiahuala de JuárezHidalgo
    0 of 31
  23. 23MonterreyNuevo León
    0 of 31
  24. 24AguascalientesAguascalientes
    0 of 31
  25. 25San Luis de la PazGuanajuato
    0 of 24
  26. 26San MarcosHidalgo
    0 of 28
  27. 27Zacatepec de HidalgoMorelos
    0 of 31
  28. 27CuernavacaMorelos
    0 of 26
  29. 29TepicNayarit
    0 of 31
  30. 30Ciudad JuárezChihuahua
    0 of 31
  31. 31ZapopanJalisco
    0 of 31
  32. 32CelayaGuanajuato
    0 of 27
  33. 33Santiago de QuerétaroQuerétaro
    0 of 31
  34. 34San Miguel de AllendeGuanajuato
    0 of 22
  35. 35TulancingoHidalgo
    0 of 26
  36. 36TehuacánPuebla
    0 of 31
  37. 37MéridaYucatán
    0 of 27
  38. 38San Juan del RíoQuerétaro
    0 of 31
  39. 39La Providencia Siglo XXIHidalgo
    0 of 31
  40. 40IrapuatoGuanajuato
    0 of 25
  41. 41Pachuca de SotoHidalgo
    0 of 31
  42. 41Heroica MatamorosTamaulipas
    0 of 30
  43. 43Victoria de DurangoDurango
    0 of 30
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, October 2025 · Mexico now

Regions

Aguascalientes 1Baja California 2Chiapas 1Chihuahua 1Coahuila 1Durango 1Guanajuato 6Hidalgo 5Jalisco 4México 3Mexico City 1Morelos 2Nayarit 1Nuevo León 6Puebla 3Querétaro 2Sonora 1Tamaulipas 1Yucatán 1

Ranked cities in each region, October 2025.

Use this board

SmogRank, most polluted cities in Mexico, by unhealthy days, PM2.5, October 2025, smogrank.com/mx/history/2025-10?by=days (accessed 7 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.