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. 1801White CenterWashington, United States 0%1 of 285
  2. 1802NavanLeinster, Ireland 0%1 of 285
  3. =1803Beaumont-sur-OiseÎle-de-France, France 0%1 of 285
  4. =1803AngoulêmeNew Aquitaine, France 0%1 of 285
  5. 1805La Ferté-MacéNormandy, France 0%1 of 285
  6. 1806Wake ForestNorth Carolina, United States 0%1 of 286
  7. 1807São PauloSão Paulo, Brazil 0%1 of 286
  8. 1808Corpus ChristiTexas, United States 0%1 of 286
  9. 1809Bruck an der MurStyria, Austria 0%1 of 286
  10. 1810NiceProvence-Alpes-Côte d'Azur, France 0%1 of 286
  11. 1811HoustonTexas, United States 0%1 of 286
  12. 1812AnaheimCalifornia, United States 0%1 of 286
  13. =1813NancyGrand Est, France 0%1 of 286
  14. =1813Granite CityIllinois, United States 0%1 of 286
  15. 1815SchwazTyrol, Austria 0%1 of 286
  16. 1816Sankt PöltenLower Austria, Austria 0%1 of 286
  17. 1817MödlingLower Austria, Austria 0%1 of 286
  18. 1818LuxembourgLuxembourg, Luxembourg 0%1 of 286
  19. =1819GapProvence-Alpes-Côte d'Azur, France 0%1 of 286
  20. =1819SokolovCarlsbad Region, Czechia 0%1 of 286
  21. =1819ChanuteKansas, United States 0%1 of 286
  22. =1822VeurneFlanders, Belgium 0%1 of 286
  23. =1822East Saint LouisIllinois, United States 0%1 of 286
  24. 1824LondonEngland, United Kingdom 0%1 of 286
  25. =1825ManzanaresCastille-La Mancha, Spain 0%1 of 286
  26. =1825BaselBasel-City, Switzerland 0%1 of 286
  27. 1827DublinOhio, United States 0%1 of 286
  28. 1828PhoenixArizona, United States 0%1 of 286
  29. 1829ReimsGrand Est, France 0%1 of 286
  30. =1830PoitiersNew Aquitaine, France 0%1 of 286
  31. =1830Chalon-sur-SaôneBourgogne-Franche-Comté, France 0%1 of 286
  32. 1832Cedar RapidsIowa, United States 0%1 of 286
  33. =1833RichmondVirginia, United States 0%1 of 286
  34. =1833RochesterMinnesota, United States 0%1 of 286
  35. =1835LorientBrittany, France 0%1 of 286
  36. =1835BrandermillVirginia, United States 0%1 of 286
  37. =1837ÉvreuxNormandy, France 0%1 of 286
  38. =1837JacksonvilleFlorida, United States 0%1 of 286
  39. 1839ChartresCentre-Val de Loire, France 0%1 of 286
  40. =1840LiègeWallonia, Belgium 0%1 of 286
  41. =1840MoulinsAuvergne-Rhône-Alpes, France 0%1 of 286
  42. 1842RoanokeVirginia, United States 0%1 of 286
  43. 1843SpringfieldMassachusetts, United States 0%1 of 286
  44. 1844BrocktonMassachusetts, United States 0%1 of 286
  45. 1845Deerfield BeachFlorida, United States 0%1 of 286
  46. 1846BostonMassachusetts, United States 0%1 of 286
  47. 1847GlendaleArizona, United States 0%1 of 286
  48. 1848KostelMunicipality of Kostel, Slovenia 0%1 of 286
  49. 1849LynnMassachusetts, United States 0%1 of 286
  50. 1850Grants PassOregon, United States 0%1 of 286
  51. 1851WorcesterMassachusetts, United States 0%1 of 286
  52. 1852QuincyMassachusetts, United States 0%1 of 286
  53. 1853AurillacAuvergne-Rhône-Alpes, France 0%1 of 286
  54. 1854North VancouverBritish Columbia, Canada 0%1 of 286
  55. 1855SatnaMadhya Pradesh, India 0%0 of 249
  56. 1856QuthbullapurTelangana, India 0%0 of 229
  57. 1857HubballiKarnataka, India 0%0 of 214
  58. 1858Kalaburagilast full day 11 OctKarnataka, India 0%0 of 233
  59. 1859NaduvattamTamil Nadu, India 0%0 of 236
  60. 1860HuascoAtacama, Chile 0%0 of 279
  61. 1861Santa AnitaJalisco, Mexico 0%0 of 206
  62. 1862CalamaAntofagasta, Chile 0%0 of 267
  63. 1863Salamancalast full day 11 OctGuanajuato, Mexico 0%0 of 227
  64. 1864Nakhon NayokNakhon Nayok, Thailand 0%0 of 257
  65. 1865Alto Hospiciolast full day 11 OctTarapacá, Chile 0%0 of 244
  66. =1866DurgChhattisgarh, India 0%0 of 251
  67. =1866KaohsiungTakao, Taiwan 0%0 of 281
  68. 1868San Luis de la Pazlast full day 11 OctGuanajuato, Mexico 0%0 of 217
  69. 1869TulancingoHidalgo, Mexico 0%0 of 286
  70. 1870NantouTaiwan, Taiwan 0%0 of 276
  71. 1871San Juan del RíoQuerétaro, Mexico 0%0 of 247
  72. =1872SrinagarJammu and Kashmir, India 0%0 of 228
  73. =1872PuliTaiwan, Taiwan 0%0 of 277
  74. 1874BuziTaiwan, Taiwan 0%0 of 276
  75. =1875TaichungTaiwan, Taiwan 0%0 of 281
  76. =1875ChanghuaTaiwan, Taiwan 0%0 of 281
  77. 1877OnomichiHiroshima, Japan 0%0 of 274
  78. 1878Limeiralast full day 5 OctSão Paulo, Brazil 0%0 of 258
  79. 1879Tula de AllendeHidalgo, Mexico 0%0 of 232
  80. 1880Imperial BeachCalifornia, United States 0%0 of 286
  81. 1881BuyeoChungcheongnam-do, South Korea 0%0 of 260
  82. 1882LuguTaiwan, Taiwan 0%0 of 281
  83. =1883MiaoliTaiwan, Taiwan 0%0 of 281
  84. =1883XizhiTaipei, Taiwan 0%0 of 280
  85. =1883BoseongJeollanam-do, South Korea 0%0 of 264
  86. =1886TaipeiTaiwan, Taiwan 0%0 of 281
  87. =1886JundiaíSão Paulo, Brazil 0%0 of 243
  88. =1886Guanajuatolast full day 11 OctGuanajuato, Mexico 0%0 of 210
  89. =1889PhatthalungPhatthalung, Thailand 0%0 of 256
  90. =1889SaijōEhime, Japan 0%0 of 282
  91. =1889New Taipei CityTaipei, Taiwan 0%0 of 281
  92. 1892CorcoranCalifornia, United States 0%0 of 285
  93. =1893ShenzhenTaiwan, Taiwan 0%0 of 281
  94. =1893XizhouTaiwan, Taiwan 0%0 of 280
  95. =1895HsinchuTaiwan, Taiwan 0%0 of 279
  96. =1895ZumarragaBasque Country, Spain 0%0 of 238
  97. =1895TaoyuanTaiwan, Taiwan 0%0 of 281
  98. =1898São José do Rio PretoSão Paulo, Brazil 0%0 of 282
  99. =1898Ribeirão PretoSão Paulo, Brazil 0%0 of 281
  100. 1900TrangTrang, Thailand 0%0 of 249

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).