SmogRank / World / Mexico / December 2025

Most unhealthy days in Mexico, December 2025

46 cities in Mexico ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Tijuana, Mexico, 19 of 28 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.

← Tijuana 68% 60%0
Every city in Mexico ranked for December 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. 1TijuanaBaja California
    19 of 28
  2. 2Hacienda Santa FeJalisco
    19 of 30
  3. 3XonacatlánMéxico
    18 of 30
  4. 4MexicaliBaja California
    17 of 31
  5. 5AguascalientesAguascalientes
    16 of 31
  6. 6GuadalajaraJalisco
    12 of 31
  7. 7Ciudad Benito JuárezNuevo León
    11 of 31
  8. 8San Antonio la IslaMéxico
    8 of 31
  9. 9Ciudad NezahualcoyotlMéxico
    8 of 31
  10. 10Zacatepec de HidalgoMorelos
    4 of 31
  11. 11TuxtlaChiapas
    2 of 27
  12. 12Santa CatarinaNuevo León
    2 of 31
  13. 13CuernavacaMorelos
    1 of 24
  14. 14IrapuatoGuanajuato
    1 of 28
  15. 15Silao de la VictoriaGuanajuato
    1 of 28
  16. 16San Martin Texmelucan de LabastidaPuebla
    1 of 28
  17. 17Mixquiahuala de JuárezHidalgo
    1 of 30
  18. 18Ciudad General EscobedoNuevo León
    1 of 30
  19. 19Santa AnitaJalisco
    1 of 31
  20. 20Naucalpan de JuárezMéxico
    1 of 31
  21. 21Mexico CityMexico City
    1 of 31
  22. 22NogalesSonora
    1 of 31
  23. 23ZapopanJalisco
    1 of 31
  24. 24PueblaPuebla
    0 of 31
  25. 25Cadereyta JiménezNuevo León
    0 of 27
  26. 25TepicNayarit
    0 of 31
  27. 27CelayaGuanajuato
    0 of 28
  28. 28León de los AldamaGuanajuato
    0 of 23
  29. 29AbasoloGuanajuato
    0 of 23
  30. 30SalamancaGuanajuato
    0 of 28
  31. 31La Providencia Siglo XXIHidalgo
    0 of 28
  32. 32TulancingoHidalgo
    0 of 31
  33. 33San Luis de la PazGuanajuato
    0 of 25
  34. 34MonterreyNuevo León
    0 of 31
  35. 35TlaxcalaTlaxcala
    0 of 24
  36. 35Santiago de QuerétaroQuerétaro
    0 of 31
  37. 35PesqueríaNuevo León
    0 of 27
  38. 38Ciudad JuárezChihuahua
    0 of 31
  39. 39GarcíaNuevo León
    0 of 26
  40. 40TehuacánPuebla
    0 of 22
  41. 40San Juan del RíoQuerétaro
    0 of 31
  42. 40San Miguel de AllendeGuanajuato
    0 of 28
  43. 43La PazBaja California Sur
    0 of 29
  44. 44Heroica MatamorosTamaulipas
    0 of 31
  45. 45MéridaYucatán
    0 of 27
  46. 46Victoria 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, December 2025 · Mexico now

Regions

Aguascalientes 1Baja California 2Baja California Sur 1Chiapas 1Chihuahua 1Durango 1Guanajuato 8Hidalgo 3Jalisco 4México 4Mexico City 1Morelos 2Nayarit 1Nuevo León 7Puebla 3Querétaro 2Sonora 1Tamaulipas 1Yucatán 1

Ranked cities in each region, December 2025.

Use this board

SmogRank, most polluted cities in Mexico, by unhealthy days, PM2.5, December 2025, smogrank.com/mx/history/2025-12?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.