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. 1001Grand CentreAlberta, Canada 2%5 of 286
  2. 1002PortageIndiana, United States 2%4 of 234
  3. 1003ChrastavaLiberec Region, Czechia 2%4 of 239
  4. 1004MiddletonWisconsin, United States 2%4 of 240
  5. 1005DouglasGeorgia, United States 2%4 of 241
  6. 1006BarneveldGelderland, The Netherlands 2%4 of 242
  7. 1007DakarDakar, Senegal 2%4 of 243
  8. 1008IrákleionCrete, Greece 2%4 of 247
  9. 1009Eagle PassTexas, United States 2%4 of 247
  10. 1010Hua HinPrachuap Khiri Khan, Thailand 2%4 of 248
  11. 1011GoseongGyeongsangnam-do, South Korea 2%4 of 251
  12. 1012ZwanenburgNorth Holland, The Netherlands 2%4 of 252
  13. 1013HouthalenFlanders, Belgium 2%4 of 253
  14. 1014HollandMichigan, United States 2%4 of 253
  15. 1015ChumphonChumphon, Thailand 2%4 of 254
  16. 1016BasildonEngland, United Kingdom 2%4 of 257
  17. 1017OmegnaPiedmont, Italy 2%4 of 258
  18. 1018Ponggae-dongJeju-do, South Korea 2%4 of 258
  19. 1019Landshutlast full day 10 OctBavaria, Germany 2%4 of 259
  20. 1020Hood RiverOregon, United States 2%4 of 259
  21. 1021BergenVestland, Norway 2%4 of 260
  22. 1022LunterenGelderland, The Netherlands 2%4 of 261
  23. 1023MoscowIdaho, United States 2%4 of 262
  24. 1024SchiedamSouth Holland, The Netherlands 2%4 of 263
  25. 1025Sault Ste. MarieOntario, Canada 2%4 of 263
  26. 1026IstanbulIstanbul, Turkey 2%4 of 264
  27. 1027LopikUtrecht, The Netherlands 2%4 of 264
  28. 1028TilburgNorth Brabant, The Netherlands 2%4 of 265
  29. 1029Speyerlast full day 10 OctRheinland-Pfalz, Germany 1%4 of 267
  30. 1030Jeju CityJeju-do, South Korea 1%4 of 268
  31. 1031YorkPennsylvania, United States 1%4 of 269
  32. 1032AlbanyGeorgia, United States 1%4 of 269
  33. 1033EstevanSaskatchewan, Canada 1%4 of 270
  34. 1034Völklingenlast full day 10 OctSaarland, Germany 1%4 of 272
  35. 1035CallaoCallao, Peru 1%3 of 204
  36. 1036SchlusserPennsylvania, United States 1%4 of 273
  37. 1037EnschedeOverijssel, The Netherlands 1%4 of 273
  38. 1038AllistonOntario, Canada 1%4 of 273
  39. 1039Saarbrückenlast full day 10 OctSaarland, Germany 1%4 of 274
  40. 1040Kaiserslauternlast full day 10 OctRheinland-Pfalz, Germany 1%4 of 275
  41. 1041AltoonaWisconsin, United States 1%4 of 275
  42. 1042's-GravenzandeSouth Holland, The Netherlands 1%4 of 276
  43. 1043ArrasHauts-de-France, France 1%4 of 276
  44. 1044LockwoodMontana, United States 1%4 of 276
  45. 1045Swift CurrentSaskatchewan, Canada 1%4 of 276
  46. 1046Sweet HomeOregon, United States 1%3 of 207
  47. 1047Velsen-ZuidNorth Holland, The Netherlands 1%4 of 277
  48. 1048Beaver FallsPennsylvania, United States 1%4 of 277
  49. 1049ElkhartIndiana, United States 1%4 of 277
  50. =1050ZaanstadNorth Holland, The Netherlands 1%4 of 277
  51. =1050Red DeerAlberta, Canada 1%4 of 277
  52. 1052East ChicagoIndiana, United States 1%4 of 277
  53. 1053Wesellast full day 10 OctNorth Rhine-Westphalia, Germany 1%4 of 277
  54. 1054PatersonNew Jersey, United States 1%4 of 277
  55. 1055DoltonIllinois, United States 1%4 of 278
  56. 1056KourouGuyane, French Guiana 1%4 of 278
  57. 1057Wilhelmshavenlast full day 10 OctLower Saxony, Germany 1%4 of 278
  58. 1058NewmarketOntario, Canada 1%4 of 278
  59. 1059MississaugaOntario, Canada 1%4 of 278
  60. 1060ManlleuCatalonia, Spain 1%4 of 279
  61. 1061BridgeviewIllinois, United States 1%4 of 279
  62. 1062SteubenvilleOhio, United States 1%4 of 279
  63. 1063LebanonPennsylvania, United States 1%4 of 279
  64. 1064BrantfordOntario, Canada 1%4 of 279
  65. 1065WyomissingPennsylvania, United States 1%4 of 279
  66. 1066Miltonlast full day 9 OctOntario, Canada 1%4 of 279
  67. 1067Mexico CityMexico City, Mexico 1%4 of 280
  68. =1068Neu-Ulmlast full day 10 OctBavaria, Germany 1%4 of 280
  69. =1068Augsburglast full day 10 OctBavaria, Germany 1%4 of 280
  70. =1068Calumet CityIllinois, United States 1%4 of 280
  71. =1068Oak LawnIllinois, United States 1%4 of 280
  72. 1072KehlBaden-Wurttemberg, Germany 1%4 of 280
  73. 1073Borkenlast full day 10 OctNorth Rhine-Westphalia, Germany 1%4 of 280
  74. 1074Buffalolast full day 11 OctNew York, United States 1%4 of 280
  75. =1075Kelsterbachlast full day 10 OctHesse, Germany 1%4 of 280
  76. =1075AmiensHauts-de-France, France 1%4 of 280
  77. 1077GuelphOntario, Canada 1%4 of 280
  78. 1078Klötzelast full day 10 OctSaxony-Anhalt, Germany 1%4 of 280
  79. 1079KasselHesse, Germany 1%4 of 281
  80. 1080Norderneylast full day 10 OctLower Saxony, Germany 1%4 of 281
  81. 1081MedinaOhio, United States 1%4 of 281
  82. 1082WieslochBaden-Wurttemberg, Germany 1%4 of 281
  83. 1083TauberbischofsheimBaden-Wurttemberg, Germany 1%4 of 281
  84. 1084Göttingenlast full day 10 OctLower Saxony, Germany 1%4 of 281
  85. 1085Weirtonlast full day 10 OctWest Virginia, United States 1%4 of 281
  86. 1086BarrieOntario, Canada 1%4 of 281
  87. 1087PopradPrešov Region, Slovakia 1%4 of 282
  88. 1088OregonOhio, United States 1%4 of 282
  89. 1089LancasterPennsylvania, United States 1%4 of 282
  90. 1090KarlsruheBaden-Wurttemberg, Germany 1%4 of 282
  91. =1091StuttgartBaden-Wurttemberg, Germany 1%4 of 282
  92. =1091Münsterlast full day 10 OctNorth Rhine-Westphalia, Germany 1%4 of 282
  93. 1093FriedrichshafenBaden-Wurttemberg, Germany 1%4 of 282
  94. 1094LudwigsburgBaden-Wurttemberg, Germany 1%4 of 282
  95. =1095Bielefeldlast full day 10 OctNorth Rhine-Westphalia, Germany 1%4 of 282
  96. =1095TaylorMichigan, United States 1%4 of 282
  97. =1097PforzheimBaden-Wurttemberg, Germany 1%4 of 282
  98. =1097NepeanOntario, Canada 1%4 of 282
  99. 1099HeidelbergBaden-Wurttemberg, Germany 1%4 of 282
  100. 1100KitchenerOntario, Canada 1%4 of 282

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).