SmogRank / History / September 4, 2023

Most polluted cities on September 4, 2023

1,847 cities ranked by their average PM2.5 over the day; the worst was Piedras Negras, Mexico, at 986.0 µg/m³. Each city's own local calendar day.

Bad-air episodes during September 4, 2023. All episodes.

← Piedras Negras 986.0 µg/m³ 900 µg/m³15 WHO 24-hour guideline
Every city ranked for September 4, 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. 1Piedras NegrasCoahuila, Mexico
    500+65.7×
  2. 2Swift CurrentSaskatchewan, Canada
    28013.7×
  3. 3ReginaSaskatchewan, Canada
    25111.7×
  4. 4SaskatoonSaskatchewan, Canada
    25011.7×
  5. 5Prince AlbertSaskatchewan, Canada
    24611.4×
  6. 6CalgaryAlberta, Canada
    2189.5×
  7. 7Puerto MonttLos Lagos Region, Chile
    1947.8×
  8. 8Medicine HatAlberta, Canada
    1897.3×
  9. 9Red DeerAlberta, Canada
    1877.2×
  10. 10CosladaMadrid, Spain
    1877.1×
  11. 11EdmontonAlberta, Canada
    1846.9×
  12. 12CuencaCastille-La Mancha, Spain
    1826.7×
  13. 13OsornoLos Lagos Region, Chile
    1786.3×
  14. 14AirdrieAlberta, Canada
    1786.2×
  15. 15CoyhaiqueAysén, Chile
    1766.1×
  16. 16Puerto VarasLos Lagos Region, Chile
    1725.7×
  17. 17LethbridgeAlberta, Canada
    1715.6×
  18. 18Great FallsMontana, United States
    1675.2×
  19. 19San CarlosÑuble, Chile
    1604.6×
  20. 20Prince GeorgeBritish Columbia, Canada
    1574.3×
  21. 21KigaliKigali, Rwanda
    1564.2×
  22. 21Puerto AysénAysén, Chile
    1564.2×
  23. 23Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    1554.1×
  24. 24BillingsMontana, United States
    1523.8×
  25. 25BeijingBeijing, China
    1523.8×
  26. 26San Luis PotosíSan Luis Potosí, Mexico
    1513.7×
  27. 27Dhakalow-cost sensorsDhaka Division, Bangladesh
    1503.7×
  28. 28Şabāḩ as SālimMubārak al Kabīr, Kuwait
    1453.6×
  29. 28KamloopsBritish Columbia, Canada
    1453.6×
  30. 30St. AlbertAlberta, Canada
    1393.4×
  31. 31Sherwood ParkAlberta, Canada
    1373.3×
  32. 32La UniónLos Ríos Region, Chile
    1293.1×
  33. 33ChillánÑuble, Chile
    1202.9×
  34. 34TorreviejaValencia, Spain
    1192.9×
  35. 35AlgiersAlgiers, Algeria
    1192.9×
  36. 36DushanbeDushanbe, Tajikistan
    1172.8×
  37. 37ShenyangLiaoning, China
    1162.8×
  38. 38Lahorelow-cost sensorsPunjab, Pakistan
    1152.7×
  39. 39BrandonManitoba, Canada
    1132.7×
  40. 40Victoria de DurangoDurango, Mexico
    1062.5×
  41. 41EldaValencia, Spain
    1052.5×
  42. 42Thunder BayOntario, Canada
    1052.5×
  43. 43Wan ChaiWan Chai, Hong Kong
    1052.5×
  44. 44Addis AbabaAddis Ababa, Ethiopia
    1042.5×
  45. 45ToméBiobio, Chile
    1032.4×
  46. 46JakartaJakarta, Indonesia
    1022.4×
  47. 47TemucoAraucania, Chile
    992.3×
  48. 48Grande PrairieAlberta, Canada
    972.3×
  49. 49ValdiviaLos Ríos Region, Chile
    962.2×
  50. 49MexicaliBaja California, Mexico
    962.2×
  51. 51Ulu BedokSingapore
    952.2×
  52. 52CuranilahueBiobio, Chile
    952.2×
  53. 53DelhiDelhi, India
    932.1×
  54. 54Kampalalow-cost sensorsCentral Region, Uganda
    922.1×
  55. 55HelenaMontana, United States
    922.1×
  56. 56SheridanWyoming, United States
    902.0×
  57. 56VernonBritish Columbia, Canada
    902.0×
  58. 58RengoO'Higgins Region, Chile
    902.0×
  59. 59CoronelBiobio, Chile
    892.0×
  60. 60NairobiNairobi County, Kenya
    892.0×
  61. 61TalcahuanoBiobio, Chile
    871.9×
  62. 62CauquenesMaule Region, Chile
    871.9×
  63. 63GuangzhouGuangdong, China
    871.9×
  64. 64HualquiBiobio, Chile
    861.9×
  65. 65Los ÁngelesBiobio, Chile
    851.8×
  66. 66BamakoBamako, Mali
    841.8×
  67. 66ZapopanJalisco, Mexico
    841.8×
  68. 66GilletteWyoming, United States
    841.8×
  69. 69Fort McMurrayAlberta, Canada
    831.7×
  70. 70IyoEhime, Japan
    821.7×
  71. 71RancaguaO'Higgins Region, Chile
    821.7×
  72. 72ConcónValparaiso, Chile
    821.7×
  73. 73Santa Anita - Los FicusLima region, Peru
    821.7×
  74. 74Ang Mo Kio New TownSingapore
    811.7×
  75. 74Puente AltoSantiago Metropolitan, Chile
    811.7×
  76. 74CuricóMaule Region, Chile
    811.7×
  77. 74LimaLima Province, Peru
    811.7×
  78. 78SarajevoFederation of B&H, Bosnia and Herzegovina
    811.7×
  79. 79BakuBaki, Azerbaijan
    811.7×
  80. 79ChennaiTamil Nadu, India
    811.7×
  81. 81Tuen MunTuen Mun, Hong Kong
    801.6×
  82. 81Sham Shui PoSham Shui Po District, Hong Kong
    801.6×
  83. 83Kuala LumpurKuala Lumpur, Malaysia
    801.6×
  84. 84SantiagoSantiago Metropolitan, Chile
    791.6×
  85. 85HanoiHanoi, Vietnam
    791.6×
  86. 86Fort-de-FranceMartinique, Martinique
    791.6×
  87. 86ChiguayanteBiobio, Chile
    791.6×
  88. 88PristinaPristina, Kosovo
    781.6×
  89. 89San Tung Chung HangIslands, Hong Kong
    781.6×
  90. 90BolzanoTrentino-Alto Adige, Italy
    781.6×
  91. 91Sau Mau PingKwun Tong District, Hong Kong
    771.6×
  92. 91Gasteiz / VitoriaBasque Country, Spain
    771.6×
  93. 91NewburghNew York, United States
    771.6×
  94. 94Le RobertMartinique, Martinique
    771.5×
  95. 95BexleyEngland, United Kingdom
    771.5×
  96. 96Tin Shui WaiYuen Long, Hong Kong
    771.5×
  97. 97QuillotaValparaiso, Chile
    761.5×
  98. 98Ciudad ApodacaNuevo León, Mexico
    761.5×
  99. 99Kwai ChungKwai Tsing District, Hong Kong
    761.5×
  100. 99SherbrookeQuebec, Canada
    761.5×
  101. 101Mong KokYau Tsim Mong District, Hong Kong
    761.5×
  102. 101Queenstown Estatelow-cost sensorsSingapore
    761.5×
  103. 101XonacatlánMéxico, Mexico
    761.5×
  104. 101San Francisco TlalcilalcalpanMéxico, Mexico
    761.5×
  105. 105Tsuen WanTsuen Wan, Hong Kong
    751.5×
  106. 105Le LamentinMartinique, Martinique
    751.5×
  107. 107CoquimboCoquimbo Region, Chile
    751.5×
  108. 108ConcepciónBiobio, Chile
    751.5×
  109. 108Lexingtonlow-cost sensorsMassachusetts, United States
    751.5×
  110. 110HyderabadTelangana, India
    741.4×
  111. 110Sha TinSha Tin, Hong Kong
    741.4×
  112. 110Naucalpan de JuárezMéxico, Mexico
    741.4×
  113. 110QuinteroValparaiso, Chile
    741.4×
  114. 114Karachilow-cost sensorsSindh, Pakistan
    741.4×
  115. 115LotaBiobio, Chile
    741.4×
  116. 116TalcaMaule Region, Chile
    731.4×
  117. 116AricaArica y Parinacota Region, Chile
    731.4×
  118. 116AntofagastaAntofagasta, Chile
    731.4×
  119. 116Alto HospicioTarapacá, Chile
    731.4×
  120. 116Gómez PalacioDurango, Mexico
    731.4×
  121. 121SuperiorWisconsin, United States
    731.4×
  122. 122TalaganteSantiago Metropolitan, Chile
    721.4×
  123. 122San Pedro de la PazBiobio, Chile
    721.4×
  124. 124KolkataWest Bengal, India
    721.4×
  125. 124GuadalajaraJalisco, Mexico
    721.4×
  126. 126Santa CatarinaNuevo León, Mexico
    721.4×
  127. 127CholulaPuebla, Mexico
    711.3×
  128. 128VictoriaCentral and Western, Hong Kong
    711.3×
  129. 129AlicanteValencia, Spain
    711.3×
  130. 130DuluthMinnesota, United States
    701.3×
  131. 130IndioCalifornia, United States
    701.3×
  132. 132PalenciaCastille and León, Spain
    701.3×
  133. 132CelayaGuanajuato, Mexico
    701.3×
  134. 134FanlingNorth District, Hong Kong
    691.3×
  135. 135CalamaAntofagasta, Chile
    691.3×
  136. 136AntananarivoAnalamanga, Madagascar
    691.2×
  137. 137DurangoBasque Country, Spain
    691.2×
  138. 137Viña del MarValparaiso, Chile
    691.2×
  139. 139MonterreyNuevo León, Mexico
    681.2×
  140. 140CopiapóAtacama, Chile
    681.2×
  141. 141ŁukówLublin, Poland
    681.2×
  142. 141Kan’onjichōKagawa, Japan
    681.2×
  143. 141LondonEngland, United Kingdom
    681.2×
  144. 144Tai PoTai Po, Hong Kong
    681.2×
  145. 145SaguenayQuebec, Canada
    671.2×
  146. 146TocopillaAntofagasta, Chile
    671.2×
  147. 147BilbaoBasque Country, Spain
    671.2×
  148. 148San JoséSan José, Costa Rica
    661.2×
  149. 149MadridMadrid, Spain
    661.2×
  150. 149UticaNew York, United States
    661.2×
  151. 151Ciudad JuárezChihuahua, Mexico
    661.1×
  152. 152AmmanAmman, Jordan
    661.1×
  153. 152CalahorraLa Rioja, Spain
    661.1×
  154. 154ShikokuchūōEhime, Japan
    651.1×
  155. 155Tula de AllendeHidalgo, Mexico
    651.1×
  156. 155Tepeji del Río de OcampoHidalgo, Mexico
    651.1×
  157. 157MumbaiMaharashtra, India
    651.1×
  158. 157Samut SakhonSamut Sakhon, Thailand
    651.1×
  159. 157Nong KhaemBangkok, Thailand
    651.1×
  160. 160Jardines de la SillaNuevo León, Mexico
    641.1×
  161. 161NiihamaEhime, Japan
    641.1×
  162. 161SalamancaGuanajuato, Mexico
    641.1×
  163. 161BurnsvilleMinnesota, United States
    641.1×
  164. 161ElizabethNew Jersey, United States
    641.1×
  165. 165Ciudad General EscobedoNuevo León, Mexico
    641.1×
  166. 165L'Ancienne-LoretteQuebec, Canada
    641.1×
  167. 165YatomiAichi, Japan
    641.1×
  168. 168DębicaSubcarpathia, Poland
    641.1×
  169. 168MonsWallonia, Belgium
    641.1×
  170. 168LourdesOccitanie, France
    641.1×
  171. 168SaltilloCoahuila, Mexico
    641.1×
  172. 168New BrunswickNew Jersey, United States
    641.1×
  173. 173DunkirkHauts-de-France, France
    641.1×
  174. 173ShakopeeMinnesota, United States
    641.1×
  175. 173San Salvador TizatlalliMéxico, Mexico
    641.1×
  176. 176HonmachiKumamoto, Japan
    631.1×
  177. 176AlmeríaAndalusia, Spain
    631.1×
  178. 176DagenhamEngland, United Kingdom
    631.1×
  179. 176BurgosCastille and León, Spain
    631.1×
  180. 180JeddahMecca Region, Saudi Arabia
    631.0×
  181. 181Ciudad NezahualcoyotlMéxico, Mexico
    631.0×
  182. 182BirminghamAlabama, United States
    631.0×
  183. 183SpringdaleArkansas, United States
    631.0×
  184. 183DerbyKansas, United States
    631.0×
  185. 183PortlandMaine, United States
    631.0×
  186. 186GraysEngland, United Kingdom
    631.0×
  187. 186NaplesCampania, Italy
    631.0×
  188. 186WichitaKansas, United States
    631.0×
  189. 186BrooklinOntario, Canada
    631.0×
  190. 190TolucaMéxico, Mexico
    621.0×
  191. 191JesiThe Marches, Italy
    621.0×
  192. 191HartfordConnecticut, United States
    621.0×
  193. 191Saint MichaelMinnesota, United States
    621.0×
  194. 191Saint PaulMinnesota, United States
    621.0×
  195. 195SalorTashkent Region, Uzbekistan
    621.0×
  196. 195Tha BoNong Khai, Thailand
    621.0×
  197. 195AlessandriaPiedmont, Italy
    621.0×
  198. 195La SerenaCoquimbo Region, Chile
    621.0×
  199. 195RochesterMinnesota, United States
    621.0×
  200. 195Saint CloudMinnesota, United States
    621.0×

Top 200 of 1,847 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 4, 2023, smogrank.com/history/2023-09-04 (accessed 2 Oct 2026).

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