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. 601Bragadirulast full day 10 OctIlfov, Romania 5%13 of 279
  2. 602Buftealast full day 10 OctIlfov, Romania 5%13 of 279
  3. 603SlatinaSouth Moravian, Czechia 5%13 of 279
  4. 604Oranienburglast full day 10 OctBrandenburg, Germany 5%13 of 279
  5. 605Airway HeightsWashington, United States 5%13 of 280
  6. 606GwangjuGwangju, South Korea 5%13 of 282
  7. 607GdyniaPomerania, Poland 5%13 of 282
  8. 608Jilavalast full day 10 OctIlfov, Romania 5%13 of 282
  9. 609JasłoSubcarpathia, Poland 5%13 of 282
  10. 610Magdeburglast full day 10 OctSaxony-Anhalt, Germany 5%13 of 282
  11. 611SopotPomerania, Poland 5%13 of 283
  12. 612TrenčínTrenčín Region, Slovakia 5%11 of 240
  13. 613Schwedt (Oder)Brandenburg, Germany 5%13 of 284
  14. 614SuwałkiPodlasie, Poland 5%13 of 284
  15. 615CranbrookBritish Columbia, Canada 5%11 of 241
  16. 616Piatra NeamţNeamț County, Romania 5%13 of 285
  17. 617Murska SobotaUrban Municipality of Murska Sobota, Slovenia 5%13 of 286
  18. 618ElblągWarmia-Masuria, Poland 5%13 of 286
  19. 619Mahlowlast full day 10 OctBrandenburg, Germany 5%12 of 264
  20. 620SandpointIdaho, United States 5%12 of 264
  21. 621RēzekneRēzekne, Latvia 5%11 of 243
  22. 622PortoPorto, Portugal 4%12 of 267
  23. 623VernonBritish Columbia, Canada 4%11 of 246
  24. 624YangguGangwon-do, South Korea 4%12 of 269
  25. 625SzegedCsongrád, Hungary 4%12 of 269
  26. 626Samut PrakanSamut Prakan, Thailand 4%11 of 248
  27. 627BudapestBudapest, Hungary 4%12 of 271
  28. 628Merseburglast full day 10 OctSaxony-Anhalt, Germany 4%12 of 273
  29. 629KomárnoNitra Region, Slovakia 4%12 of 274
  30. 630EphrataWashington, United States 4%12 of 274
  31. 631PécsBaranya, Hungary 4%12 of 277
  32. 632SantyokuGangwon-do, South Korea 4%12 of 279
  33. 633ImsilJeollabuk-do, South Korea 4%12 of 279
  34. 634Ciudad Benito JuárezNuevo León, Mexico 4%11 of 256
  35. 635GyálPest County, Hungary 4%11 of 256
  36. 636Stralsundlast full day 10 OctMecklenburg-Vorpommern, Germany 4%12 of 280
  37. 637EsztergomKomárom-Esztergom, Hungary 4%12 of 281
  38. 638UlsanUlsan, South Korea 4%12 of 282
  39. 639Cluj-Napocalast full day 10 OctCluj County, Romania 4%12 of 282
  40. 640Wittenberglast full day 10 OctSaxony-Anhalt, Germany 4%12 of 282
  41. 641Halle (Saale)last full day 10 OctSaxony-Anhalt, Germany 4%12 of 282
  42. 642Zalăulast full day 10 OctSălaj County, Romania 4%12 of 282
  43. 643KlaipėdaKlaipėda County, Lithuania 4%10 of 236
  44. 644KošiceKošice Region, Slovakia 4%12 of 284
  45. 645MartinŽilina Region, Slovakia 4%12 of 284
  46. 646Brandenburg an der HavelBrandenburg, Germany 4%12 of 284
  47. 647QuincyWashington, United States 4%12 of 284
  48. 648NajuJeollanam-do, South Korea 4%11 of 261
  49. 649MeadWashington, United States 4%12 of 285
  50. 650KatowiceSilesia, Poland 4%12 of 286
  51. 651GrazStyria, Austria 4%12 of 286
  52. 652ThiruvananthapuramKerala, India 4%10 of 239
  53. 653NeietsuGangwon-do, South Korea 4%11 of 267
  54. 654BraPiedmont, Italy 4%10 of 244
  55. 655Teltowlast full day 10 OctBrandenburg, Germany 4%11 of 269
  56. 656Naucalpan de JuárezMéxico, Mexico 4%10 of 245
  57. 657Berlinlast full day 11 OctState of Berlin, Germany 4%11 of 270
  58. 658Royal OakMichigan, United States 4%9 of 222
  59. 659MortaraLombardy, Italy 4%11 of 273
  60. 660Dessaulast full day 10 OctSaxony-Anhalt, Germany 4%11 of 273
  61. 661Otopenilast full day 10 OctIlfov, Romania 4%11 of 275
  62. 662LimaLima Province, Peru 4%8 of 202
  63. 663HopeBritish Columbia, Canada 4%11 of 278
  64. 664FanlingNorth District, Hong Kong 4%8 of 203
  65. 665Hamburglast full day 10 OctHamburg, Germany 4%11 of 280
  66. 666SenecBratislava Region, Slovakia 4%11 of 281
  67. 667Timişoaralast full day 10 OctTimiș County, Romania 4%9 of 230
  68. 668Voluntarilast full day 10 OctIlfov, Romania 4%11 of 282
  69. 669Chorvátsky Grob - Čierna VodaBratislava Region, Slovakia 4%11 of 282
  70. 670Frankfurt (Oder)Brandenburg, Germany 4%11 of 282
  71. 671Mühlhausenlast full day 10 OctThuringia, Germany 4%11 of 282
  72. 672CottbusBrandenburg, Germany 4%11 of 284
  73. 673TepliceÚstí nad Labem Region, Czechia 4%11 of 286
  74. 674BratislavaBratislava Region, Slovakia 4%11 of 286
  75. 675SeosanChungcheongnam-do, South Korea 4%10 of 263
  76. 676KochaniKochani, North Macedonia 4%8 of 211
  77. 677Naujoji AkmeneSiauliai, Lithuania 4%10 of 270
  78. 678DeltaColorado, United States 4%10 of 270
  79. 679MokpoJeollanam-do, South Korea 4%10 of 277
  80. 680Königs Wusterhausenlast full day 10 OctBrandenburg, Germany 4%10 of 277
  81. 681Nocera InferioreCampania, Italy 4%9 of 250
  82. 682MalackyBratislava Region, Slovakia 4%10 of 279
  83. 683Luckenwaldelast full day 10 OctBrandenburg, Germany 4%10 of 279
  84. 684PezinokBratislava Region, Slovakia 4%10 of 280
  85. 685RayongRayong, Thailand 4%9 of 252
  86. 686BorgomaneroPiedmont, Italy 4%9 of 252
  87. 687Hradec KrálovéHradec Králové Region, Czechia 4%10 of 281
  88. 688WawerMazovia, Poland 4%10 of 281
  89. 689Oldenburglast full day 10 OctLower Saxony, Germany 4%10 of 281
  90. 690TrebinjeSrpska, Bosnia and Herzegovina 4%10 of 281
  91. 691Iaşilast full day 10 OctIași County, Romania 4%10 of 282
  92. 692LubnjowBrandenburg, Germany 4%10 of 282
  93. 693StrausbergBrandenburg, Germany 4%10 of 282
  94. 694MostÚstí nad Labem Region, Czechia 4%10 of 283
  95. 695Bad BelzigBrandenburg, Germany 4%10 of 283
  96. 696HadongGyeongsangnam-do, South Korea 4%8 of 227
  97. 697NauenBrandenburg, Germany 4%10 of 284
  98. 698PotsdamBrandenburg, Germany 4%10 of 284
  99. 699BusanBusan, South Korea 4%10 of 285
  100. 700HodonínSouth Moravian, Czechia 3%10 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).