SmogRank / Rankings

All 3,198 cities by unhealthy days, this year

Every city with enough measurements in this window, worst first.

CPCB in India: no readings since 12 Oct (488 monitors). EEA in Spain: no readings since 13 Oct (310 monitors). Their cities show older figures or are missing from this board, not clean.

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. Cities with the same share are ordered by more unhealthy days, then by the higher average.

  1. 901TrentoTrentino-Alto Adige, Italy 2%5 of 266
  2. 902VictoriaCentral and Western, Hong Kong 2%4 of 213
  3. 903KolárovoNitra Region, Slovakia 2%5 of 268
  4. 904SinhyeonGyeongsangnam-do, South Korea 2%5 of 269
  5. 905SevlievoGabrovo, Bulgaria 2%5 of 269
  6. 906WyomingMichigan, United States 2%5 of 271
  7. 907Fort Saskatchewanlast full day 28 SeptAlberta, Canada 2%5 of 271
  8. 908Lauenburglast full day 10 OctSchleswig-Holstein, Germany 2%5 of 271
  9. 909HartlepoolEngland, United Kingdom 2%5 of 272
  10. 910DenainHauts-de-France, France 2%5 of 273
  11. 911RedfordMichigan, United States 2%5 of 274
  12. 912BeigangTaiwan, Taiwan 2%5 of 275
  13. 913Bozemanlast full day 10 OctMontana, United States 2%5 of 275
  14. 914SunnysideWashington, United States 2%5 of 276
  15. 915BradfordEngland, United Kingdom 2%5 of 276
  16. 916Goslarlast full day 10 OctLower Saxony, Germany 2%5 of 276
  17. =917Emdenlast full day 10 OctLower Saxony, Germany 2%5 of 277
  18. =917ValenciennesHauts-de-France, France 2%5 of 277
  19. 919MaassluisSouth Holland, The Netherlands 2%5 of 277
  20. 920WaterdownOntario, Canada 2%5 of 277
  21. 921Pachuca de SotoHidalgo, Mexico 2%4 of 222
  22. 922Alcalá de GuadairaAndalusia, Spain 2%5 of 278
  23. 923Greizlast full day 10 OctThuringia, Germany 2%5 of 278
  24. 924AmsterdamNorth Holland, The Netherlands 2%5 of 278
  25. 925ButteMontana, United States 2%5 of 278
  26. 926SuncheonJeollanam-do, South Korea 2%5 of 279
  27. 927ZvolenBanská Bystrica Region, Slovakia 2%5 of 279
  28. 928Schwäbisch HallBaden-Wurttemberg, Germany 2%5 of 279
  29. 929Bützowlast full day 10 OctMecklenburg-Vorpommern, Germany 2%5 of 279
  30. 930LuganoTicino, Switzerland 2%5 of 280
  31. 931Malchowlast full day 10 OctMecklenburg-Vorpommern, Germany 2%5 of 280
  32. 932Duderstadtlast full day 10 OctLower Saxony, Germany 2%5 of 280
  33. 933FengshanTakao, Taiwan 2%5 of 281
  34. 934TainanTaiwan, Taiwan 2%5 of 281
  35. 935LiberecLiberec Region, Czechia 2%5 of 281
  36. 936ElginIllinois, United States 2%5 of 281
  37. 937Munichlast full day 11 OctBavaria, Germany 2%5 of 281
  38. 938Rostocklast full day 10 OctMecklenburg-Vorpommern, Germany 2%5 of 281
  39. =939Nordhausenlast full day 10 OctThuringia, Germany 2%5 of 281
  40. =939RangioraCanterbury, New Zealand 2%5 of 281
  41. =941Osnabrücklast full day 10 OctLower Saxony, Germany 2%5 of 281
  42. =941SouthfieldMichigan, United States 2%5 of 281
  43. 943Güstrowlast full day 10 OctMecklenburg-Vorpommern, Germany 2%5 of 281
  44. 944Lüneburglast full day 10 OctLower Saxony, Germany 2%5 of 281
  45. =945BredaNorth Brabant, The Netherlands 2%5 of 281
  46. =945Lingenlast full day 10 OctLower Saxony, Germany 2%5 of 281
  47. 947Rintelnlast full day 10 OctLower Saxony, Germany 2%5 of 281
  48. =948The HagueSouth Holland, The Netherlands 2%5 of 282
  49. =948LampertheimHesse, Germany 2%5 of 282
  50. =950ReutlingenBaden-Wurttemberg, Germany 2%5 of 282
  51. =950Jenalast full day 10 OctThuringia, Germany 2%5 of 282
  52. =950SarniaOntario, Canada 2%5 of 282
  53. 953DouaiHauts-de-France, France 2%5 of 282
  54. 954EastpointeMichigan, United States 2%5 of 282
  55. 955Sondershausenlast full day 10 OctThuringia, Germany 2%5 of 282
  56. 956AltamontOregon, United States 2%5 of 282
  57. 957KwangyangJeollanam-do, South Korea 2%5 of 283
  58. 958WaukeshaWisconsin, United States 2%5 of 283
  59. 959AirdrieAlberta, Canada 2%5 of 283
  60. 960GaryIndiana, United States 2%4 of 227
  61. 961SenicaTrnava Region, Slovakia 2%5 of 284
  62. 962MaconGeorgia, United States 2%5 of 284
  63. 963DearbornMichigan, United States 2%5 of 284
  64. =964CandelariaCanary Islands, Spain 2%5 of 284
  65. =964SulzbachHesse, Germany 2%5 of 284
  66. 966Frankfurt am MainHesse, Germany 2%5 of 284
  67. 967Limburg an der LahnHesse, Germany 2%5 of 284
  68. 968WiesbadenHesse, Germany 2%5 of 284
  69. =969Rüsselsheim am MainHesse, Germany 2%5 of 284
  70. =969DarmstadtHesse, Germany 2%5 of 284
  71. 971FuldaHesse, Germany 2%5 of 284
  72. 972MichelstadtHesse, Germany 2%5 of 284
  73. =973OytenLower Saxony, Germany 2%5 of 284
  74. =973Winthrop HarborIllinois, United States 2%5 of 284
  75. 975BeirutBeirut, Lebanon 2%5 of 285
  76. 976EvanstonIllinois, United States 2%5 of 285
  77. 977VoitsbergStyria, Austria 2%5 of 285
  78. =978LilleHauts-de-France, France 2%5 of 285
  79. =978LondonOntario, Canada 2%5 of 285
  80. 980EdmontonAlberta, Canada 2%5 of 285
  81. 981GabrovoGabrovo, Bulgaria 2%5 of 285
  82. 982St. AlbertAlberta, Canada 2%5 of 285
  83. 983Ciudad JuárezChihuahua, Mexico 2%5 of 286
  84. 984SuperiorWisconsin, United States 2%5 of 286
  85. 985MikulovSouth Moravian, Czechia 2%5 of 286
  86. 986DunkirkHauts-de-France, France 2%5 of 286
  87. 987Zagorje ob SaviMunicipality of Zagorje ob Savi, Slovenia 2%5 of 286
  88. 988ClevelandOhio, United States 2%5 of 286
  89. 989Klagenfurt am WörtherseeCarinthia, Austria 2%5 of 286
  90. 990Lincoln ParkMichigan, United States 2%5 of 286
  91. 991Grand RapidsMichigan, United States 2%5 of 286
  92. =992StrasbourgGrand Est, France 2%5 of 286
  93. =992LewistonIdaho, United States 2%5 of 286
  94. 994NorthbrookIllinois, United States 2%5 of 286
  95. 995DieppeNormandy, France 2%5 of 286
  96. 996HudsonvilleMichigan, United States 2%5 of 286
  97. 997HamiltonOntario, Canada 2%5 of 286
  98. 998TorontoOntario, Canada 2%5 of 286
  99. 999ToppenishWashington, United States 2%5 of 286
  100. 1000PullmanWashington, United States 2%5 of 286

What stands behind each figure: Checked at 2+ sites One reference monitor Low-cost sensors About these marks

Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.

Good0–50
Moderate51–100
Unhealthy for 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

Not covered: the government monitoring networks of China, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.

Use this board

SmogRank, all cities ranked by unhealthy days (PM2.5), this year to 14 Oct 2026, 07:00 UTC: each city's share of its measured days with a daily mean over 35.4 µg/m³, cities measured on 70% or more of the days since 1 January (at least 14). Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/rankings?w=year&by=days. Ranked on low-cost sensors, with no reference monitor in the city: #4 Kampala and #8 Faisalabad. Some values from Sensor.Community, ODbL. Some readings from Department of Environment, Nepal; Vietnam's government monitors; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published.

Download top 10 by average (PNG)

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.

Updated 2026-10-14 07:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Department of Environment, Nepal; Vietnam's government monitors; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published (why we use them).