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. 801Erfurtlast full day 10 OctThuringia, Germany 2%7 of 282
  2. 802WittenbergeBrandenburg, Germany 2%7 of 282
  3. 803Thalelast full day 10 OctSaxony-Anhalt, Germany 2%7 of 282
  4. 804Liptovský Mikulᚎilina Region, Slovakia 2%7 of 283
  5. 805ChangwonGyeongsangnam-do, South Korea 2%7 of 284
  6. 806BogatyniaLower Silesia, Poland 2%7 of 284
  7. 807New HollandPennsylvania, United States 2%7 of 284
  8. 808BebraHesse, Germany 2%7 of 284
  9. 809Wittingenlast full day 30 SeptLower Saxony, Germany 2%5 of 203
  10. 810PueblaPuebla, Mexico 2%7 of 285
  11. 811UngsangGyeongsangnam-do, South Korea 2%7 of 285
  12. 812BareillyUttar Pradesh, India 2%6 of 245
  13. 813CeljeUrban Municipality of Celje, Slovenia 2%7 of 286
  14. =814Ústí nad LabemÚstí nad Labem Region, Czechia 2%7 of 286
  15. =814JihlavaVysocina, Czechia 2%7 of 286
  16. 816Nova GoricaUrban Municipality of Nova Gorica, Slovenia 2%7 of 286
  17. 817GeojeGyeongsangnam-do, South Korea 2%6 of 249
  18. 818VallettaValletta, Malta 2%6 of 252
  19. 819Columbia CityWashington, United States 2%6 of 252
  20. 820Grande PrairieAlberta, Canada 2%6 of 253
  21. 821La SerenaCoquimbo Region, Chile 2%6 of 258
  22. 822Holbocalast full day 10 OctIași County, Romania 2%5 of 215
  23. 823BéthuneHauts-de-France, France 2%6 of 259
  24. 824EindhovenNorth Brabant, The Netherlands 2%6 of 260
  25. 825Tai PoTai Po, Hong Kong 2%5 of 217
  26. 826VilniusVilnius, Lithuania 2%6 of 264
  27. 827Visalialast full day 6 OctCalifornia, United States 2%6 of 265
  28. 828RidderkerkSouth Holland, The Netherlands 2%6 of 266
  29. 829Irapuatolast full day 11 OctGuanajuato, Mexico 2%5 of 222
  30. 830Mong KokYau Tsim Mong District, Hong Kong 2%5 of 222
  31. 831Novi SadVojvodina, Serbia 2%5 of 224
  32. 832SolofraCampania, Italy 2%6 of 269
  33. 833PerchtoldsdorfLower Austria, Austria 2%6 of 269
  34. 834Kleinmachnowlast full day 10 OctBrandenburg, Germany 2%6 of 269
  35. 835Neuwiedlast full day 10 OctRheinland-Pfalz, Germany 2%6 of 272
  36. 836NišCentral Serbia, Serbia 2%5 of 227
  37. 837VeszprémVeszprém, Hungary 2%6 of 274
  38. 838Dillingenlast full day 10 OctSaarland, Germany 2%6 of 274
  39. 839NijmegenGelderland, The Netherlands 2%6 of 274
  40. 840KladnoCentral Bohemia, Czechia 2%6 of 275
  41. 841SpijkenisseSouth Holland, The Netherlands 2%6 of 275
  42. 842KlosterneuburgLower Austria, Austria 2%6 of 276
  43. 843ChaniáCrete, Greece 2%6 of 277
  44. 844Neuruppinlast full day 11 OctBrandenburg, Germany 2%6 of 277
  45. 845WaalreNorth Brabant, The Netherlands 2%6 of 277
  46. =846GroningenGroningen, The Netherlands 2%6 of 278
  47. =846Lüchowlast full day 10 OctLower Saxony, Germany 2%6 of 278
  48. 848ChilliwackBritish Columbia, Canada 2%6 of 278
  49. 849NeuenhagenBrandenburg, Germany 2%5 of 232
  50. 850TrnavaTrnava Region, Slovakia 2%6 of 279
  51. 851Great FallsMontana, United States 2%6 of 279
  52. 852Jorklast full day 10 OctLower Saxony, Germany 2%6 of 279
  53. 853Green BayWisconsin, United States 2%6 of 279
  54. 854HaskovoHaskovo, Bulgaria 2%6 of 279
  55. 855Chiayi CityTaiwan, Taiwan 2%6 of 280
  56. 856GiubiascoTicino, Switzerland 2%6 of 280
  57. 857Ludwigshafen am Rheinlast full day 10 OctRheinland-Pfalz, Germany 2%6 of 280
  58. 858Westerlandlast full day 10 OctSchleswig-Holstein, Germany 2%6 of 280
  59. 859Walsrodelast full day 10 OctLower Saxony, Germany 2%6 of 280
  60. 860Mainzlast full day 10 OctRheinland-Pfalz, Germany 2%6 of 280
  61. 861GreendaleWisconsin, United States 2%6 of 280
  62. 862YakimaWashington, United States 2%6 of 280
  63. 863Mladá BoleslavCentral Bohemia, Czechia 2%6 of 281
  64. 864EisenzickenBurgenland, Austria 2%6 of 281
  65. 865LethbridgeAlberta, Canada 2%6 of 281
  66. 866MannheimBaden-Wurttemberg, Germany 2%6 of 282
  67. =867UlmBaden-Wurttemberg, Germany 2%6 of 282
  68. =867HeilbronnBaden-Wurttemberg, Germany 2%6 of 282
  69. 869Altenburglast full day 10 OctThuringia, Germany 2%6 of 282
  70. 870TübingenBaden-Wurttemberg, Germany 2%6 of 282
  71. 871Bottroplast full day 10 OctNorth Rhine-Westphalia, Germany 2%6 of 282
  72. 872Geralast full day 10 OctThuringia, Germany 2%6 of 282
  73. 873ModestoCalifornia, United States 2%6 of 282
  74. 874GijangBusan, South Korea 2%6 of 283
  75. 875HnúšťaBanská Bystrica Region, Slovakia 2%6 of 283
  76. 876RotterdamSouth Holland, The Netherlands 2%6 of 283
  77. 877RužomberokŽilina Region, Slovakia 2%6 of 284
  78. 878Elmwood ParkIllinois, United States 2%6 of 285
  79. 879EnnisMunster, Ireland 2%6 of 285
  80. 880MarquetteMichigan, United States 2%6 of 285
  81. 881EllensburgWashington, United States 2%6 of 285
  82. 882Fort McMurrayAlberta, Canada 2%6 of 285
  83. =883LjubljanaLjubljana, Slovenia 2%6 of 286
  84. =883FresnoCalifornia, United States 2%6 of 286
  85. 885EisenstadtBurgenland, Austria 2%6 of 286
  86. 886OconomowocWisconsin, United States 2%6 of 286
  87. =887DetroitMichigan, United States 2%6 of 286
  88. =887WindsorOntario, Canada 2%6 of 286
  89. 889RoubaixHauts-de-France, France 2%6 of 286
  90. 890ViennaVienna, Austria 2%6 of 286
  91. 891New BaltimoreMichigan, United States 2%6 of 286
  92. 892AppletonWisconsin, United States 2%6 of 286
  93. 893ManisteeMichigan, United States 2%6 of 286
  94. 894BendOregon, United States 2%6 of 286
  95. 895WormerNorth Holland, The Netherlands 2%5 of 242
  96. 896KollumFriesland, The Netherlands 2%5 of 256
  97. 897CalaisHauts-de-France, France 2%5 of 259
  98. 898Bayonnelast full day 11 OctNew Jersey, United States 2%5 of 260
  99. 899JangheungJeollanam-do, South Korea 2%5 of 262
  100. 900ChangnyeongGyeongsangnam-do, South Korea 2%5 of 263

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).