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. 501ŽarnovicaBanská Bystrica Region, Slovakia 7%19 of 281
  2. 502Moravská Třeboválast full day 11 OctPardubice Region, Czechia 7%19 of 283
  3. 503YangjuGyeonggi-do, South Korea 7%18 of 269
  4. 504Uijeongbu-siGyeonggi-do, South Korea 7%19 of 284
  5. 505Zielona GóraLubusz, Poland 7%19 of 284
  6. 506PřerovOlomouc Region, Czechia 7%19 of 285
  7. 507IlindenIlinden, North Macedonia 7%19 of 285
  8. 508HayangGyeongsangbuk-do, South Korea 7%18 of 270
  9. 509StudénkaMoravian-Silesian Region, Czechia 7%19 of 286
  10. 510LublinLublin, Poland 7%19 of 286
  11. 511GdańskPomerania, Poland 7%19 of 286
  12. 512GyőrGyőr-Moson-Sopron, Hungary 7%19 of 286
  13. 513SzczecinWest Pomerania, Poland 7%19 of 286
  14. 514Baker CityOregon, United States 7%19 of 286
  15. 515KamloopsBritish Columbia, Canada 7%18 of 271
  16. 516Ohridlast full day 10 OctOhrid, North Macedonia 6%18 of 277
  17. 517NonsanChungcheongnam-do, South Korea 6%18 of 278
  18. 518PúchovTrenčín Region, Slovakia 6%18 of 279
  19. 519EłkWarmia-Masuria, Poland 6%18 of 280
  20. 520YeongdongNorth Chungcheong, South Korea 6%16 of 251
  21. 521JungpyongNorth Chungcheong, South Korea 6%17 of 267
  22. 522PohangGyeongsangbuk-do, South Korea 6%18 of 284
  23. 523ŽilinaŽilina Region, Slovakia 6%18 of 284
  24. 524WaegwanGyeongsangbuk-do, South Korea 6%17 of 269
  25. 525Jinan-gunlast full day 8 OctJeollabuk-do, South Korea 6%16 of 254
  26. 526ŁódźŁódź Voivodeship, Poland 6%18 of 286
  27. 527Gyeongsan-siGyeongsangbuk-do, South Korea 6%18 of 286
  28. =528BiałystokPodlasie, Poland 6%18 of 286
  29. =528DěčínÚstí nad Labem Region, Czechia 6%18 of 286
  30. 530KościerzynaPomerania, Poland 6%18 of 286
  31. 531CastlegarBritish Columbia, Canada 6%16 of 255
  32. 532HaenamJeollanam-do, South Korea 6%15 of 240
  33. 533MasanGwangju, South Korea 6%17 of 274
  34. 534Ban Khlong PrawetBangkok, Thailand 6%16 of 258
  35. 535La GrandeOregon, United States 6%17 of 277
  36. 536VentspilsVentspils, Latvia 6%14 of 230
  37. 537OščadnicaŽilina Region, Slovakia 6%17 of 282
  38. 538HumennéPrešov Region, Slovakia 6%17 of 284
  39. 539LučenecBanská Bystrica Region, Slovakia 6%16 of 268
  40. 540PołaniecŚwiętokrzyskie, Poland 6%17 of 286
  41. 541WarsawMazovia, Poland 6%17 of 286
  42. 542Ciudad NezahualcoyotlMéxico, Mexico 6%13 of 219
  43. 543OntarioOregon, United States 6%16 of 272
  44. 544ChangsuJeollabuk-do, South Korea 6%16 of 273
  45. 545Buri RamBuriram, Thailand 6%15 of 257
  46. 546KunwiGyeongsangbuk-do, South Korea 6%15 of 258
  47. 547AndongGyeongsangbuk-do, South Korea 6%15 of 259
  48. 548EisenGyeongsangbuk-do, South Korea 6%15 of 260
  49. 549Calafatlast full day 10 OctDolj, Romania 6%13 of 227
  50. 550KohimaNagaland, India 6%14 of 245
  51. 551DaejeonDaejeon, South Korea 6%16 of 282
  52. 552BresciaLombardy, Italy 6%16 of 282
  53. 553Bernburglast full day 10 OctSaxony-Anhalt, Germany 6%16 of 282
  54. 554San Francisco De BorjaLima region, Peru 6%12 of 212
  55. 555OlsztynWarmia-Masuria, Poland 6%16 of 283
  56. 556KroměřížZlín, Czechia 6%16 of 285
  57. 557BelgradeCentral Serbia, Serbia 6%16 of 286
  58. 558DaeguDaegu, South Korea 6%16 of 286
  59. 559PtujUrban Municipality of Ptuj, Slovenia 6%16 of 286
  60. 560WinterthurZurich, Switzerland 6%16 of 286
  61. 561NovaraPiedmont, Italy 6%14 of 252
  62. 562KielceŚwiętokrzyskie, Poland 5%15 of 273
  63. 563Koch'angJeollabuk-do, South Korea 5%14 of 258
  64. 564GongjuChungcheongnam-do, South Korea 5%15 of 278
  65. 565MungyeongGyeongsangbuk-do, South Korea 5%14 of 261
  66. 566EisenhüttenstadtBrandenburg, Germany 5%15 of 282
  67. 567Zeitzlast full day 10 OctSaxony-Anhalt, Germany 5%15 of 282
  68. 568Santa Lucíalast full day 11 OctCanary Islands, Spain 5%13 of 245
  69. 569BerounCentral Bohemia, Czechia 5%15 of 284
  70. 570Vranov nad TopľouPrešov Region, Slovakia 5%15 of 285
  71. 571PłockMazovia, Poland 5%15 of 285
  72. 572Taesal-liChungcheongnam-do, South Korea 5%14 of 266
  73. 573YeongamJeollanam-do, South Korea 5%14 of 266
  74. 574ZlínZlín, Czechia 5%14 of 268
  75. 575ShivamoggaKarnataka, India 5%11 of 212
  76. 576KołobrzegWest Pomerania, Poland 5%14 of 271
  77. 577Piteştilast full day 10 OctArges, Romania 5%11 of 214
  78. 578Weißenfelslast full day 10 OctSaxony-Anhalt, Germany 5%14 of 277
  79. 579JeonjuJeollabuk-do, South Korea 5%14 of 278
  80. 580TrebišovKošice Region, Slovakia 5%14 of 278
  81. 581Burg bei Magdeburglast full day 10 OctSaxony-Anhalt, Germany 5%14 of 279
  82. 582Suceavalast full day 10 OctSuceava, Romania 5%14 of 280
  83. 583HraniceOlomouc Region, Czechia 5%14 of 280
  84. 584BoiseIdaho, United States 5%14 of 280
  85. 585GuadalajaraJalisco, Mexico 5%14 of 282
  86. 586Stendallast full day 10 OctSaxony-Anhalt, Germany 5%14 of 282
  87. 587ZiguinchorZiguinchor, Senegal 5%14 of 283
  88. 588Moses LakeWashington, United States 5%13 of 263
  89. 589KrosnoSubcarpathia, Poland 5%14 of 284
  90. 590HwawŏnDaegu, South Korea 5%13 of 265
  91. 591WenatcheeWashington, United States 5%14 of 286
  92. 592YecheonGyeongsangbuk-do, South Korea 5%13 of 266
  93. 593Hongch’ŏnGangwon-do, South Korea 5%13 of 268
  94. 594Cheongsong gunGyeongsangbuk-do, South Korea 5%13 of 268
  95. 595PyeongchangGangwon-do, South Korea 5%11 of 228
  96. 596AccraGreater Accra, Ghana 5%12 of 250
  97. 597San Pedro SulaCortés Department, Honduras 5%13 of 272
  98. 598ChinjuGyeongsangnam-do, South Korea 5%13 of 273
  99. 599ChuncheonGangwon-do, South Korea 5%13 of 278
  100. 600KaunasKaunas, Lithuania 5%13 of 278

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).