SmogRank / History / September 23, 2023

Most polluted cities on September 23, 2023

1,877 cities ranked by their average PM2.5 over the day; the worst was Puerto Varas, Chile, at 75.3 µg/m³. Each city's own local calendar day.

Bad-air episodes during September 23, 2023. All episodes.

← Puerto Varas 75.3 µg/m³ 70 µg/m³15 WHO 24-hour guideline
Every city ranked for September 23, 2023, one column each, worst on the left and cleanest on the right; height is PM2.5 in µg/m³. Point at it to read a city; tap to open it.
  1. 1Puerto VarasLos Lagos Region, Chile
    1655.0×
  2. 2AshlandOregon, United States
    1644.9×
  3. 3MedfordOregon, United States
    1594.5×
  4. 4CauquenesMaule Region, Chile
    1473.6×
  5. 5Kampalalow-cost sensorsCentral Region, Uganda
    1433.5×
  6. 6CoyhaiqueAysén, Chile
    1333.2×
  7. 7OsornoLos Lagos Region, Chile
    1323.2×
  8. 8La UniónLos Ríos Region, Chile
    1273.1×
  9. 9RoseburgOregon, United States
    1212.9×
  10. 10Grants PassOregon, United States
    1192.9×
  11. 11GuangzhouGuangdong, China
    1182.8×
  12. 12PristinaPristina, Kosovo
    1172.8×
  13. 13Santa Anita - Los FicusLima region, Peru
    1162.8×
  14. 14DelhiDelhi, India
    1152.7×
  15. 15RancaguaO'Higgins Region, Chile
    1142.7×
  16. 16Addis AbabaAddis Ababa, Ethiopia
    1122.7×
  17. 17Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    1122.7×
  18. 18Puente AltoSantiago Metropolitan, Chile
    1122.7×
  19. 19Puerto MonttLos Lagos Region, Chile
    1112.6×
  20. 20AthensAttica, Greece
    1072.5×
  21. 21San Francisco TlalcilalcalpanMéxico, Mexico
    1002.4×
  22. 22Şabāḩ as SālimMubārak al Kabīr, Kuwait
    1002.4×
  23. 22MexicaliBaja California, Mexico
    1002.4×
  24. 24AsprópyrgosAttica, Greece
    992.3×
  25. 25AltamontOregon, United States
    992.3×
  26. 26JakartaJakarta, Indonesia
    992.3×
  27. 27SantiagoSantiago Metropolitan, Chile
    982.3×
  28. 28LimaLima Province, Peru
    982.3×
  29. 29BendOregon, United States
    982.3×
  30. 30Lagoslow-cost sensorsLagos, Nigeria
    972.2×
  31. 31RengoO'Higgins Region, Chile
    962.2×
  32. 32Villa Poeta José Gálvez BarrenecheaLima region, Peru
    962.2×
  33. 33CholulaPuebla, Mexico
    952.2×
  34. 34TlaquepaqueJalisco, Mexico
    922.1×
  35. 35Dhakalow-cost sensorsDhaka Division, Bangladesh
    922.1×
  36. 36HualquiBiobio, Chile
    902.0×
  37. 37PiraeusAttica, Greece
    892.0×
  38. 38Lahorelow-cost sensorsPunjab, Pakistan
    892.0×
  39. 39RedmondOregon, United States
    892.0×
  40. 40FontanaCalifornia, United States
    881.9×
  41. 41TijuanaBaja California, Mexico
    881.9×
  42. 42SarajevoFederation of B&H, Bosnia and Herzegovina
    871.9×
  43. 42BirminghamAlabama, United States
    871.9×
  44. 44Little RockArkansas, United States
    861.9×
  45. 45XonacatlánMéxico, Mexico
    851.8×
  46. 45MaderaCalifornia, United States
    851.8×
  47. 47TolucaMéxico, Mexico
    851.8×
  48. 48AcharnésAttica, Greece
    851.8×
  49. 49TurlockCalifornia, United States
    841.8×
  50. 50KhalándrionAttica, Greece
    831.8×
  51. 50AnaheimCalifornia, United States
    831.8×
  52. 50HanfordCalifornia, United States
    831.8×
  53. 50SalinasCalifornia, United States
    831.8×
  54. 54OceansideCalifornia, United States
    831.8×
  55. 55Santa CatarinaNuevo León, Mexico
    831.7×
  56. 56ComptonCalifornia, United States
    821.7×
  57. 56LompocCalifornia, United States
    821.7×
  58. 56VisaliaCalifornia, United States
    821.7×
  59. 59FresnoCalifornia, United States
    821.7×
  60. 60CuricóMaule Region, Chile
    811.7×
  61. 60Torrancelow-cost sensorsCalifornia, United States
    811.7×
  62. 62TemucoAraucania, Chile
    811.7×
  63. 62Carsonlow-cost sensorsCalifornia, United States
    811.7×
  64. 64PleasantonCalifornia, United States
    811.7×
  65. 65CorcoranCalifornia, United States
    811.7×
  66. 66RichmondCalifornia, United States
    811.7×
  67. 67MantecaCalifornia, United States
    801.7×
  68. 68Arroyo GrandeCalifornia, United States
    801.6×
  69. 68ModestoCalifornia, United States
    801.6×
  70. 70Los AngelesCalifornia, United States
    801.6×
  71. 70NipomoCalifornia, United States
    801.6×
  72. 72HanoiHanoi, Vietnam
    801.6×
  73. 72ValdiviaLos Ríos Region, Chile
    801.6×
  74. 72MercedCalifornia, United States
    801.6×
  75. 72Jurupa ValleyCalifornia, United States
    801.6×
  76. 72Santa BarbaraCalifornia, United States
    801.6×
  77. 77BakersfieldCalifornia, United States
    791.6×
  78. 78San Luis ObispoCalifornia, United States
    791.6×
  79. 79Inglewoodlow-cost sensorsCalifornia, United States
    791.6×
  80. 79OaklandCalifornia, United States
    791.6×
  81. 81SliemaTas-Sliema, Malta
    791.6×
  82. 81San JoseCalifornia, United States
    791.6×
  83. 81StocktonCalifornia, United States
    791.6×
  84. 84BakuBaki, Azerbaijan
    781.6×
  85. 85Shakaskraallow-cost sensorsKwaZulu-Natal, South Africa
    781.6×
  86. 85NacimientoBiobio, Chile
    781.6×
  87. 85San FranciscoCalifornia, United States
    781.6×
  88. 88Agouralow-cost sensorsCalifornia, United States
    781.6×
  89. 88ClovisCalifornia, United States
    781.6×
  90. 88Lomitalow-cost sensorsCalifornia, United States
    781.6×
  91. 88PortervilleCalifornia, United States
    781.6×
  92. 88Santa Monicalow-cost sensorsCalifornia, United States
    781.6×
  93. 93Ang Mo Kio New TownSingapore
    781.6×
  94. 93Ciudad JuárezChihuahua, Mexico
    781.6×
  95. 93Hawthornelow-cost sensorsCalifornia, United States
    781.6×
  96. 96El CajonCalifornia, United States
    781.6×
  97. 97BurbankCalifornia, United States
    771.5×
  98. 97Long BeachCalifornia, United States
    771.5×
  99. 97PowayCalifornia, United States
    771.5×
  100. 100Redwood CityCalifornia, United States
    771.5×
  101. 100Thousand OaksCalifornia, United States
    771.5×
  102. 102San DiegoCalifornia, United States
    771.5×
  103. 102TracyCalifornia, United States
    771.5×
  104. 102La Crescenta-Montroselow-cost sensorsCalifornia, United States
    771.5×
  105. 105LivermoreCalifornia, United States
    771.5×
  106. 106TalaganteSantiago Metropolitan, Chile
    761.5×
  107. 106San CarlosÑuble, Chile
    761.5×
  108. 106RiversideCalifornia, United States
    761.5×
  109. 109CoronelBiobio, Chile
    761.5×
  110. 110GlendoraCalifornia, United States
    761.5×
  111. 111NairobiNairobi County, Kenya
    751.5×
  112. 112DavisCalifornia, United States
    751.5×
  113. 113Puerto AysénAysén, Chile
    751.5×
  114. 113CopiapóAtacama, Chile
    751.5×
  115. 113WoodlandCalifornia, United States
    751.5×
  116. 113Yuba CityCalifornia, United States
    751.5×
  117. 117ToméBiobio, Chile
    741.4×
  118. 117GaltCalifornia, United States
    741.4×
  119. 117OrcuttCalifornia, United States
    741.4×
  120. 120Phra PradaengSamut Prakan, Thailand
    741.4×
  121. 120BangkokBangkok, Thailand
    741.4×
  122. 122Ulu BedokSingapore
    741.4×
  123. 122FolsomCalifornia, United States
    741.4×
  124. 122San LeandroCalifornia, United States
    741.4×
  125. 125San RafaelCalifornia, United States
    741.4×
  126. 126AntofagastaAntofagasta, Chile
    731.4×
  127. 127Santa ClaritaCalifornia, United States
    731.4×
  128. 128MiskolcBorsod-Abaúj-Zemplén, Hungary
    731.4×
  129. 128ConcordCalifornia, United States
    731.4×
  130. 130QuillotaValparaiso, Chile
    731.4×
  131. 130CallaoCallao, Peru
    731.4×
  132. 130Ciudad ApodacaNuevo León, Mexico
    731.4×
  133. 133NishioAichi, Japan
    721.4×
  134. 133PueblaPuebla, Mexico
    721.4×
  135. 135TalcahuanoBiobio, Chile
    721.4×
  136. 135RosevilleCalifornia, United States
    721.4×
  137. 137ChillánÑuble, Chile
    721.4×
  138. 138ShenyangLiaoning, China
    721.4×
  139. 138Ciudad General EscobedoNuevo León, Mexico
    721.4×
  140. 140LincolnCalifornia, United States
    721.3×
  141. 140SacramentoCalifornia, United States
    721.3×
  142. 142Queenstown Estatelow-cost sensorsSingapore
    711.3×
  143. 142ConcónValparaiso, Chile
    711.3×
  144. 142Simi ValleyCalifornia, United States
    711.3×
  145. 145Bang Bo DistrictSamut Prakan, Thailand
    711.3×
  146. 145Ciudad NezahualcoyotlMéxico, Mexico
    711.3×
  147. 147N'DjamenaN’Djaména, Chad
    711.3×
  148. 148Nong KhaemBangkok, Thailand
    711.3×
  149. 148ZapopanJalisco, Mexico
    711.3×
  150. 148Santa CruzCalifornia, United States
    711.3×
  151. 151Islamabadlow-cost sensorsIslamabad, Pakistan
    701.3×
  152. 151São PauloSão Paulo, Brazil
    701.3×
  153. 151AricaArica y Parinacota Region, Chile
    701.3×
  154. 154SalamancaGuanajuato, Mexico
    701.3×
  155. 155AtascaderoCalifornia, United States
    701.3×
  156. 156ŻabbarĦaż-Żabbar, Malta
    701.3×
  157. 156TocopillaAntofagasta, Chile
    701.3×
  158. 158BamakoBamako, Mali
    691.3×
  159. 159QuinteroValparaiso, Chile
    691.3×
  160. 159HollisterCalifornia, United States
    691.3×
  161. 161Wan ChaiWan Chai, Hong Kong
    691.3×
  162. 161San Francisco De BorjaLima region, Peru
    691.3×
  163. 163NišCentral Serbia, Serbia
    691.2×
  164. 164Naucalpan de JuárezMéxico, Mexico
    691.2×
  165. 164Arden-ArcadeCalifornia, United States
    691.2×
  166. 166Tha BoNong Khai, Thailand
    691.2×
  167. 166CoquimboCoquimbo Region, Chile
    691.2×
  168. 166ChiguayanteBiobio, Chile
    691.2×
  169. 166GuadalajaraJalisco, Mexico
    691.2×
  170. 166Prince AlbertSaskatchewan, Canada
    691.2×
  171. 171SaltilloCoahuila, Mexico
    681.2×
  172. 172Samut PrakanSamut Prakan, Thailand
    681.2×
  173. 173SofiaSofia-Capital, Bulgaria
    681.2×
  174. 173TarnówLesser Poland, Poland
    681.2×
  175. 175Santa RosaCalifornia, United States
    671.2×
  176. 176Los ÁngelesBiobio, Chile
    671.2×
  177. 177Quezon Citylow-cost sensorsNational Capital Region, Philippines
    671.2×
  178. 177HernandoMississippi, United States
    671.2×
  179. 179KamloopsBritish Columbia, Canada
    671.2×
  180. 180KolkataWest Bengal, India
    671.2×
  181. 180ChicoCalifornia, United States
    671.2×
  182. 180GilroyCalifornia, United States
    671.2×
  183. 183CuranilahueBiobio, Chile
    661.2×
  184. 183ConcepciónBiobio, Chile
    661.2×
  185. 185LotaBiobio, Chile
    661.2×
  186. 185San Pedro de la PazBiobio, Chile
    661.2×
  187. 187Iowa CityIowa, United States
    661.1×
  188. 188Grande PrairieAlberta, Canada
    661.1×
  189. 188ReginaSaskatchewan, Canada
    661.1×
  190. 190TalcaMaule Region, Chile
    661.1×
  191. 190VacavilleCalifornia, United States
    661.1×
  192. 190EdmontonAlberta, Canada
    661.1×
  193. 193CalamaAntofagasta, Chile
    651.1×
  194. 194Accralow-cost sensorsGreater Accra, Ghana
    651.1×
  195. 195RuseRuse, Bulgaria
    641.1×
  196. 195Samut SakhonSamut Sakhon, Thailand
    641.1×
  197. 195La SerenaCoquimbo Region, Chile
    641.1×
  198. 198DębicaSubcarpathia, Poland
    641.1×
  199. 198HueytownAlabama, United States
    641.1×
  200. 200MostaIl-Mosta, Malta
    641.1×

Top 200 of 1,877 shown.

Good0–50
Moderate51–100
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

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SmogRank, most polluted cities, PM2.5, September 23, 2023, smogrank.com/history/2023-09-23 (accessed 2 Oct 2026).

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