SmogRank / History / July 21, 2023

Most polluted cities on July 21, 2023

1,286 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.

← Piedras Negras 986.0 µg/m³ 900 µg/m³15 WHO 24-hour guideline
Every city ranked for July 21, 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. 2DushanbeDushanbe, Tajikistan
    2078.8×
  3. 3CoyhaiqueAysén, Chile
    1947.8×
  4. 4Kampalalow-cost sensorsCentral Region, Uganda
    1604.6×
  5. 5RengoO'Higgins Region, Chile
    1574.3×
  6. 6Grande PrairieAlberta, Canada
    1544.0×
  7. 7AsprópyrgosAttica, Greece
    1543.9×
  8. 8EdmontonAlberta, Canada
    1523.8×
  9. 9Fort St. JohnBritish Columbia, Canada
    1503.7×
  10. 10ShenyangLiaoning, China
    1393.4×
  11. 11Lahorelow-cost sensorsPunjab, Pakistan
    1333.2×
  12. 12Puerto AysénAysén, Chile
    1323.2×
  13. 13AnconaThe Marches, Italy
    1313.2×
  14. 14SantiagoSantiago Metropolitan, Chile
    1283.1×
  15. 15RancaguaO'Higgins Region, Chile
    1263.1×
  16. 16Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    1202.9×
  17. 17Fort McMurrayAlberta, Canada
    1192.9×
  18. 18HanoiHanoi, Vietnam
    1152.7×
  19. 19DelhiDelhi, India
    1092.6×
  20. 20Puente AltoSantiago Metropolitan, Chile
    1092.6×
  21. 21TalaganteSantiago Metropolitan, Chile
    1082.6×
  22. 22Prince GeorgeBritish Columbia, Canada
    1022.4×
  23. 23AlgiersAlgiers, Algeria
    1012.4×
  24. 24Santa Anita - Los FicusLima region, Peru
    992.3×
  25. 25NacimientoBiobio, Chile
    982.3×
  26. 26PristinaPristina, Kosovo
    962.2×
  27. 27CuranilahueBiobio, Chile
    952.2×
  28. 27TlaquepaqueJalisco, Mexico
    952.2×
  29. 29SliemaTas-Sliema, Malta
    952.2×
  30. 30Karachilow-cost sensorsSindh, Pakistan
    942.2×
  31. 30CatañoCataño, Puerto Rico
    942.2×
  32. 32Şabāḩ as SālimMubārak al Kabīr, Kuwait
    932.1×
  33. 33ChennaiTamil Nadu, India
    912.1×
  34. 34MostaIl-Mosta, Malta
    902.0×
  35. 35SaskatoonSaskatchewan, Canada
    902.0×
  36. 35St. AlbertAlberta, Canada
    902.0×
  37. 37AntofagastaAntofagasta, Chile
    892.0×
  38. 38QuillotaValparaiso, Chile
    881.9×
  39. 39ŻabbarĦaż-Żabbar, Malta
    881.9×
  40. 40MexicaliBaja California, Mexico
    881.9×
  41. 41La UniónLos Ríos Region, Chile
    881.9×
  42. 42Ciudad ApodacaNuevo León, Mexico
    871.9×
  43. 43HualpénBiobio, Chile
    871.9×
  44. 44OsornoLos Lagos Region, Chile
    871.9×
  45. 45BeijingBeijing, China
    861.9×
  46. 45Prince AlbertSaskatchewan, Canada
    861.9×
  47. 47Islamabadlow-cost sensorsIslamabad, Pakistan
    861.9×
  48. 47XonacatlánMéxico, Mexico
    861.9×
  49. 49Le RobertMartinique, Martinique
    861.8×
  50. 50SarajevoFederation of B&H, Bosnia and Herzegovina
    851.8×
  51. 51Le LamentinMartinique, Martinique
    851.8×
  52. 52Sherwood ParkAlberta, Canada
    841.8×
  53. 53ReginaSaskatchewan, Canada
    841.8×
  54. 54LimaLima Province, Peru
    831.8×
  55. 55Dhakalow-cost sensorsDhaka Division, Bangladesh
    831.8×
  56. 56SaltilloCoahuila, Mexico
    831.7×
  57. 57Puerto MonttLos Lagos Region, Chile
    831.7×
  58. 58CuricóMaule Region, Chile
    821.7×
  59. 59ModugnoApulia, Italy
    801.7×
  60. 60Fort-de-FranceMartinique, Martinique
    801.6×
  61. 61SalorTashkent Region, Uzbekistan
    791.6×
  62. 62BeneventoCampania, Italy
    791.6×
  63. 63Puerto VarasLos Lagos Region, Chile
    791.6×
  64. 64UkiahCalifornia, United States
    791.6×
  65. 65BamakoBamako, Mali
    781.6×
  66. 66AthensAttica, Greece
    771.6×
  67. 67TemucoAraucania, Chile
    771.5×
  68. 68PesaroThe Marches, Italy
    771.5×
  69. 69TolucaMéxico, Mexico
    761.5×
  70. 70Falconara MarittimaThe Marches, Italy
    761.5×
  71. 70CoronelBiobio, Chile
    761.5×
  72. 72GuadalajaraJalisco, Mexico
    751.5×
  73. 73AntananarivoAnalamanga, Madagascar
    751.5×
  74. 74Swift CurrentSaskatchewan, Canada
    741.4×
  75. 75BrunswickGeorgia, United States
    741.4×
  76. 75BakersfieldCalifornia, United States
    741.4×
  77. 77Fort LauderdaleFlorida, United States
    741.4×
  78. 78VisaliaCalifornia, United States
    741.4×
  79. 79La SerenaCoquimbo Region, Chile
    731.4×
  80. 79Alto HospicioTarapacá, Chile
    731.4×
  81. 81BakuBaki, Azerbaijan
    731.4×
  82. 81SalamancaGuanajuato, Mexico
    731.4×
  83. 83San Francisco De BorjaLima region, Peru
    731.4×
  84. 84LinaresMaule Region, Chile
    721.4×
  85. 84Red DeerAlberta, Canada
    721.4×
  86. 86GuangzhouGuangdong, China
    721.4×
  87. 86Palm CityFlorida, United States
    721.4×
  88. 88Ang Mo Kio New TownSingapore
    721.4×
  89. 88NaplesCampania, Italy
    721.4×
  90. 88ValdostaGeorgia, United States
    721.4×
  91. 91PiraeusAttica, Greece
    721.3×
  92. 91ValdiviaLos Ríos Region, Chile
    721.3×
  93. 93Ulu BedokSingapore
    711.3×
  94. 94San Mateo AtencoMéxico, Mexico
    711.3×
  95. 94AricaArica y Parinacota Region, Chile
    711.3×
  96. 96Santa CatarinaNuevo León, Mexico
    711.3×
  97. 97ShreveportLouisiana, United States
    711.3×
  98. 97BrawleyCalifornia, United States
    711.3×
  99. 99TurlockCalifornia, United States
    701.3×
  100. 100CelayaGuanajuato, Mexico
    701.3×
  101. 101HualquiBiobio, Chile
    701.3×
  102. 102CalamaAntofagasta, Chile
    691.3×
  103. 102BridgeportConnecticut, United States
    691.3×
  104. 102VictorvilleCalifornia, United States
    691.3×
  105. 105Viña del MarValparaiso, Chile
    691.3×
  106. 105Ciudad JuárezChihuahua, Mexico
    691.3×
  107. 107ChillánÑuble, Chile
    691.3×
  108. 107SavannahGeorgia, United States
    691.3×
  109. 109Naucalpan de JuárezMéxico, Mexico
    691.2×
  110. 109AshlandOregon, United States
    691.2×
  111. 111CopiapóAtacama, Chile
    681.2×
  112. 111PortervilleCalifornia, United States
    681.2×
  113. 113Almatylow-cost sensorsAlmaty, Kazakhstan
    681.2×
  114. 113Los AngelesCalifornia, United States
    681.2×
  115. 115ConcónValparaiso, Chile
    681.2×
  116. 116JesiThe Marches, Italy
    681.2×
  117. 117BangkokBangkok, Thailand
    681.2×
  118. 117Ciudad Benito JuárezNuevo León, Mexico
    681.2×
  119. 117El CentroCalifornia, United States
    681.2×
  120. 120Los ÁngelesBiobio, Chile
    671.2×
  121. 120CauquenesMaule Region, Chile
    671.2×
  122. 120TexarkanaTexas, United States
    671.2×
  123. 123BitolaBitola, North Macedonia
    671.2×
  124. 123New LondonConnecticut, United States
    671.2×
  125. 123FresnoCalifornia, United States
    671.2×
  126. 123MaderaCalifornia, United States
    671.2×
  127. 127AcharnésAttica, Greece
    671.2×
  128. 127Delray BeachFlorida, United States
    671.2×
  129. 129Casa GrandeArizona, United States
    661.2×
  130. 129FontanaCalifornia, United States
    661.2×
  131. 129HanfordCalifornia, United States
    661.2×
  132. 132Phra PradaengSamut Prakan, Thailand
    661.2×
  133. 132Palm BayFlorida, United States
    661.2×
  134. 134TorreviejaValencia, Spain
    661.1×
  135. 134YumaArizona, United States
    661.1×
  136. 134ClovisCalifornia, United States
    661.1×
  137. 137Queenstown Estatelow-cost sensorsSingapore
    661.1×
  138. 137Coconut CreekFlorida, United States
    661.1×
  139. 137Great FallsMontana, United States
    661.1×
  140. 140TocopillaAntofagasta, Chile
    661.1×
  141. 140LotaBiobio, Chile
    661.1×
  142. 140Yuba CityCalifornia, United States
    661.1×
  143. 143Nong KhaemBangkok, Thailand
    661.1×
  144. 143Phenix CityAlabama, United States
    661.1×
  145. 143WellingtonFlorida, United States
    661.1×
  146. 143West FargoNorth Dakota, United States
    661.1×
  147. 147KhalándrionAttica, Greece
    651.1×
  148. 147San CarlosÑuble, Chile
    651.1×
  149. 147Missouri CityTexas, United States
    651.1×
  150. 150TijuanaBaja California, Mexico
    651.1×
  151. 150CalexicoCalifornia, United States
    651.1×
  152. 152Samut SakhonSamut Sakhon, Thailand
    651.1×
  153. 152TalcahuanoBiobio, Chile
    651.1×
  154. 152ComptonCalifornia, United States
    651.1×
  155. 155Bang Bo DistrictSamut Prakan, Thailand
    651.1×
  156. 155Belle GladeFlorida, United States
    651.1×
  157. 155Deerfield BeachFlorida, United States
    651.1×
  158. 158TalcaMaule Region, Chile
    641.1×
  159. 158Fort WorthTexas, United States
    641.1×
  160. 160AustinTexas, United States
    641.1×
  161. 160Apache JunctionArizona, United States
    641.1×
  162. 162GrossetoTuscany, Italy
    641.1×
  163. 163HoustonTexas, United States
    641.1×
  164. 163Jurupa ValleyCalifornia, United States
    641.1×
  165. 163ModestoCalifornia, United States
    641.1×
  166. 166Bishkeklow-cost sensorsBishkek, Kyrgyzstan
    641.1×
  167. 166QuinteroValparaiso, Chile
    641.1×
  168. 166San Luis PotosíSan Luis Potosí, Mexico
    641.1×
  169. 169Bang KapiBangkok, Thailand
    631.1×
  170. 169DavieFlorida, United States
    631.1×
  171. 169VeniceFlorida, United States
    631.1×
  172. 169IndioCalifornia, United States
    631.1×
  173. 173SalernoCampania, Italy
    631.0×
  174. 173Bonita SpringsFlorida, United States
    631.0×
  175. 175ColomboWestern Province, Sri Lanka
    631.0×
  176. 175Lexingtonlow-cost sensorsMassachusetts, United States
    631.0×
  177. 177BirminghamAlabama, United States
    631.0×
  178. 177MiamiFlorida, United States
    631.0×
  179. 179Wan ChaiWan Chai, Hong Kong
    631.0×
  180. 179Civitanova MarcheThe Marches, Italy
    631.0×
  181. 179LansingMichigan, United States
    631.0×
  182. 179RiversideCalifornia, United States
    631.0×
  183. 179San JoseCalifornia, United States
    631.0×
  184. 184Kathmandulow-cost sensorsBagmati Province, Nepal
    631.0×
  185. 184GyőrGyőr-Moson-Sopron, Hungary
    631.0×
  186. 184León de los AldamaGuanajuato, Mexico
    631.0×
  187. 184WoodlandCalifornia, United States
    631.0×
  188. 184San Pedro de la PazBiobio, Chile
    631.0×
  189. 189La Línea de la ConcepciónAndalusia, Spain
    621.0×
  190. 189Santiago de QuerétaroQuerétaro, Mexico
    621.0×
  191. 189KalamazooMichigan, United States
    621.0×
  192. 189CorcoranCalifornia, United States
    621.0×
  193. 193GlendoraCalifornia, United States
    621.0×
  194. 193MantecaCalifornia, United States
    621.0×
  195. 195WillebroekFlanders, Belgium
    621.0×
  196. 195CuencaCastille-La Mancha, Spain
    621.0×
  197. 197TetovoTetovo, North Macedonia
    621.0×
  198. 197NottinghamEngland, United Kingdom
    621.0×
  199. 197Ceglie MessapicaApulia, Italy
    621.0×
  200. 197HueytownAlabama, United States
    621.0×

Top 200 of 1,286 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, July 21, 2023, smogrank.com/history/2023-07-21 (accessed 2 Oct 2026).

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