SmogRank / Rankings

All 3,290 cities by unhealthy days, last 30 days

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. =789JundiaíSão Paulo, Brazil 0%0 of 30
  2. =789MonterreyNuevo León, Mexico 0%0 of 27
  3. =789LimaOhio, United States 0%0 of 28
  4. =789AraoKumamoto, Japan 0%0 of 30
  5. =805KuryeJeollanam-do, South Korea 0%0 of 28
  6. =805TřinecMoravian-Silesian Region, Czechia 0%0 of 30
  7. =807Vranov nad TopľouPrešov Region, Slovakia 0%0 of 30
  8. =807KošiceKošice Region, Slovakia 0%0 of 29
  9. =807Prileplast full day 10 OctPrilep, North Macedonia 0%0 of 24
  10. =807ChaiyaphumChaiyaphum, Thailand 0%0 of 30
  11. =807ŌmutaFukuoka, Japan 0%0 of 30
  12. =807OkazakiAichi, Japan 0%0 of 30
  13. =807KumamotoKumamoto, Japan 0%0 of 30
  14. =807MartinŽilina Region, Slovakia 0%0 of 30
  15. =807Castano PrimoLombardy, Italy 0%0 of 26
  16. =807WorcesterWestern Cape, South Africa 0%0 of 30
  17. =807Wake ForestNorth Carolina, United States 0%0 of 30
  18. =807MiddletownOhio, United States 0%0 of 30
  19. =807HawthorneCalifornia, United States 0%0 of 29
  20. =820CiechanówMazovia, Poland 0%0 of 30
  21. =820Sakon NakhonSakon Nakhon, Thailand 0%0 of 28
  22. =820ChanthaburiChanthaburi, Thailand 0%0 of 30
  23. =820ToufenTaiwan, Taiwan 0%0 of 30
  24. =820YeonilGyeongsangbuk-do, South Korea 0%0 of 30
  25. =820UlsanUlsan, South Korea 0%0 of 30
  26. =820BusanBusan, South Korea 0%0 of 29
  27. =820UtoKumamoto, Japan 0%0 of 30
  28. =820TamanaKumamoto, Japan 0%0 of 30
  29. =820IzumiKagoshima, Japan 0%0 of 30
  30. =820BeppuOita, Japan 0%0 of 29
  31. =820WolfsbergCarinthia, Austria 0%0 of 30
  32. =820Ústí nad LabemÚstí nad Labem Region, Czechia 0%0 of 30
  33. =820GdańskPomerania, Poland 0%0 of 30
  34. =820CasertaCampania, Italy 0%0 of 29
  35. =820BirminghamAlabama, United States 0%0 of 30
  36. =820OceansideCalifornia, United States 0%0 of 30
  37. =837Hua HinPrachuap Khiri Khan, Thailand 0%0 of 28
  38. =837ChumphonChumphon, Thailand 0%0 of 30
  39. =837KinzanChungcheongnam-do, South Korea 0%0 of 27
  40. =837SendaiKagoshima, Japan 0%0 of 30
  41. =837NobeokaMiyazaki, Japan 0%0 of 30
  42. =837KikuchiKumamoto, Japan 0%0 of 30
  43. =837KanoyaKagoshima, Japan 0%0 of 30
  44. =837Kędzierzyn-KoźleOpole Voivodeship, Poland 0%0 of 30
  45. =837WyomingMichigan, United States 0%0 of 30
  46. =846Strumicalast full day 10 OctStrumica, North Macedonia 0%0 of 25
  47. =846Nichinanlast full day 10 OctMiyazaki, Japan 0%0 of 27
  48. =846KariyaAichi, Japan 0%0 of 30
  49. =846KagoshimaKagoshima, Japan 0%0 of 30
  50. =846SaijōEhime, Japan 0%0 of 30
  51. =846Murcialast full day 11 OctMurcia, Spain 0%0 of 28
  52. =846RoubaixHauts-de-France, France 0%0 of 30
  53. =846TrenčínTrenčín Region, Slovakia 0%0 of 30
  54. =846HraniceOlomouc Region, Czechia 0%0 of 30
  55. =846Jelenia GóraLower Silesia, Poland 0%0 of 30
  56. =846ZarautzBasque Country, Spain 0%0 of 30
  57. =846BilbaoBasque Country, Spain 0%0 of 30
  58. =846SaldanhaWestern Cape, South Africa 0%0 of 29
  59. =846Cape Townlast full day 8 OctWestern Cape, South Africa 0%0 of 25
  60. =846Mixquiahuala de JuárezHidalgo, Mexico 0%0 of 24
  61. =846Chula VistaCalifornia, United States 0%0 of 30
  62. =846PortervilleCalifornia, United States 0%0 of 30
  63. =846TurlockCalifornia, United States 0%0 of 30
  64. =846KaniGifu, Japan 0%0 of 30
  65. =865Cluj-Napocalast full day 10 OctCluj County, Romania 0%0 of 27
  66. =865YasothonYasothon, Thailand 0%0 of 28
  67. =865YeongdongNorth Chungcheong, South Korea 0%0 of 29
  68. =865TokonameAichi, Japan 0%0 of 30
  69. =865El Planlast full day 11 OctMurcia, Spain 0%0 of 28
  70. =865Flémalle-HauteWallonia, Belgium 0%0 of 29
  71. =865DunaújvárosFejér, Hungary 0%0 of 30
  72. =865SereďTrnava Region, Slovakia 0%0 of 30
  73. =865SenecBratislava Region, Slovakia 0%0 of 28
  74. =865NitraNitra Region, Slovakia 0%0 of 30
  75. =865WschowaLubusz, Poland 0%0 of 30
  76. =865Szczytnalast full day 11 OctLower Silesia, Poland 0%0 of 28
  77. =865DurangoBasque Country, Spain 0%0 of 29
  78. =865Cava Dè TirreniCampania, Italy 0%0 of 29
  79. =865TulsaOklahoma, United States 0%0 of 29
  80. =865San JoseCalifornia, United States 0%0 of 30
  81. =865KirishimaKagoshima, Japan 0%0 of 30
  82. =865GeojeGyeongsangnam-do, South Korea 0%0 of 28
  83. =865TōkaiAichi, Japan 0%0 of 30
  84. =884EłkWarmia-Masuria, Poland 0%0 of 30
  85. =884JangseongJeollanam-do, South Korea 0%0 of 29
  86. =884IwashitaKumamoto, Japan 0%0 of 30
  87. =884FukuyamaHiroshima, Japan 0%0 of 30
  88. =884Alcantarillalast full day 11 OctMurcia, Spain 0%0 of 28
  89. =884Gelsenkirchenlast full day 10 OctNorth Rhine-Westphalia, Germany 0%0 of 27
  90. =884Augsburglast full day 10 OctBavaria, Germany 0%0 of 27
  91. =884SlatinaSouth Moravian, Czechia 0%0 of 30
  92. =884RacibórzSilesia, Poland 0%0 of 30
  93. =884LjubljanaLjubljana, Slovenia 0%0 of 30
  94. =884PaulíniaSão Paulo, Brazil 0%0 of 30
  95. =884BauruSão Paulo, Brazil 0%0 of 30
  96. =884TulancingoHidalgo, Mexico 0%0 of 30
  97. =884CarsonCalifornia, United States 0%0 of 29
  98. =884Yuba CityCalifornia, United States 0%0 of 30
  99. =884MatsusakaMie, Japan 0%0 of 30
  100. 900NishioAichi, Japan 0%0 of 30

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), last 30 days 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 21 or more of the 30 days. Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/rankings?w=30d&by=days. Ranked on low-cost sensors, with no reference monitor in the city: #1 Peshawar, #2 Multan, #5 Kasur, #7 Gujranwala, #8 Lahore, #9 Faisalabad and #10 Jammu. Some values from Sensor.Community, ODbL. Some readings from Vietnam's government monitors; Department of Environment, Nepal; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver); 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: Vietnam's government monitors; Department of Environment, Nepal; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published (why we use them).