SmogRank / History / May 18, 2023

Most polluted cities on May 18, 2023

1,569 cities ranked by their average PM2.5 over the day; the worst was Grande Prairie, Canada, at 459.0 µg/m³. Each city's own local calendar day.

Bad-air episodes during May 18, 2023. All episodes.

← Grande Prairie 459.0 µg/m³ 400 µg/m³15 WHO 24-hour guideline
Every city ranked for May 18, 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. 1Grande PrairieAlberta, Canada
    500+30.6×
  2. 2Fort St. JohnBritish Columbia, Canada
    24211.1×
  3. 3BloemfonteinFree State, South Africa
    1826.6×
  4. 4West FargoNorth Dakota, United States
    1816.6×
  5. 5NacimientoBiobio, Chile
    1796.4×
  6. 6Rapid CitySouth Dakota, United States
    1756.0×
  7. 7AberdeenSouth Dakota, United States
    1705.5×
  8. 7WatertownSouth Dakota, United States
    1705.5×
  9. 9Prince GeorgeBritish Columbia, Canada
    1695.4×
  10. 10KamloopsBritish Columbia, Canada
    1685.3×
  11. 11HualpénBiobio, Chile
    1675.2×
  12. 12BaghdadBaghdad, Iraq
    1675.2×
  13. 13Lahorelow-cost sensorsPunjab, Pakistan
    1655.0×
  14. 14CranbrookBritish Columbia, Canada
    1655.0×
  15. 15HelenaMontana, United States
    1634.8×
  16. 16BrookingsSouth Dakota, United States
    1574.3×
  17. 17San CarlosÑuble, Chile
    1564.1×
  18. 18VernonBritish Columbia, Canada
    1554.0×
  19. 19Dhakalow-cost sensorsDhaka Division, Bangladesh
    1543.9×
  20. 20ShakopeeMinnesota, United States
    1533.9×
  21. 21Los ÁngelesBiobio, Chile
    1533.9×
  22. 22TalcahuanoBiobio, Chile
    1523.8×
  23. 23HanoiHanoi, Vietnam
    1513.7×
  24. 23ToméBiobio, Chile
    1513.7×
  25. 25GilletteWyoming, United States
    1493.7×
  26. 26TalcaMaule Region, Chile
    1453.5×
  27. 27KelownaBritish Columbia, Canada
    1423.5×
  28. 28JakartaJakarta, Indonesia
    1403.4×
  29. 29Ubon RatchathaniUbon Ratchathani, Thailand
    1403.4×
  30. 30CalgaryAlberta, Canada
    1393.4×
  31. 31BurnsvilleMinnesota, United States
    1373.3×
  32. 32Apple ValleyMinnesota, United States
    1363.3×
  33. 33Ga-RankuwaNorth West, South Africa
    1363.3×
  34. 34CuranilahueBiobio, Chile
    1353.3×
  35. 35Grand IslandNebraska, United States
    1353.3×
  36. 36HualquiBiobio, Chile
    1343.2×
  37. 37Saint CloudMinnesota, United States
    1333.2×
  38. 38LinaresMaule Region, Chile
    1323.2×
  39. 39SalamancaGuanajuato, Mexico
    1323.2×
  40. 40ChillánÑuble, Chile
    1313.2×
  41. 41CauquenesMaule Region, Chile
    1273.1×
  42. 42NanNan, Thailand
    1243.0×
  43. 43MukdahanMukdahan, Thailand
    1222.9×
  44. 44RengoO'Higgins Region, Chile
    1202.9×
  45. 45HyderabadTelangana, India
    1192.8×
  46. 46ButteMontana, United States
    1172.8×
  47. 47KigaliKigali, Rwanda
    1162.8×
  48. 48CoronelBiobio, Chile
    1162.8×
  49. 49CuricóMaule Region, Chile
    1152.7×
  50. 50OsornoLos Lagos Region, Chile
    1152.7×
  51. 51Saint MichaelMinnesota, United States
    1142.7×
  52. 52CelayaGuanajuato, Mexico
    1102.6×
  53. 53SheridanWyoming, United States
    1092.6×
  54. 54MinneapolisMinnesota, United States
    1082.6×
  55. 55Puerto VarasLos Lagos Region, Chile
    1082.6×
  56. 56Tha BoNong Khai, Thailand
    1072.5×
  57. 57Si Maha PhotPrachin Buri, Thailand
    1042.5×
  58. 58PakxanBolikhamsai, Laos
    1042.4×
  59. 59TalaganteSantiago Metropolitan, Chile
    1032.4×
  60. 60Si Sa KetSi Sa Ket, Thailand
    1012.4×
  61. 61ConcepciónBiobio, Chile
    1012.4×
  62. 62Nakhon RatchasimaNakhon Ratchasima, Thailand
    1012.4×
  63. 63Kampalalow-cost sensorsCentral Region, Uganda
    1002.4×
  64. 64SantiagoSantiago Metropolitan, Chile
    992.3×
  65. 64RancaguaO'Higgins Region, Chile
    992.3×
  66. 66DelhiDelhi, India
    982.3×
  67. 66BozemanMontana, United States
    982.3×
  68. 68Mae SaiChiang Rai, Thailand
    982.3×
  69. 68Roi EtRoi Et, Thailand
    982.3×
  70. 70Bang NaBangkok, Thailand
    982.3×
  71. 71La UniónLos Ríos Region, Chile
    972.3×
  72. 72Lop BuriLopburi, Thailand
    972.2×
  73. 72BillingsMontana, United States
    972.2×
  74. 74PhetchabunPhetchabun, Thailand
    962.2×
  75. 75LoeiLoei, Thailand
    962.2×
  76. 76Khan Na YaoBangkok, Thailand
    962.2×
  77. 77UttaraditUttaradit, Thailand
    962.2×
  78. 77SaraburiSaraburi, Thailand
    962.2×
  79. 77GuangzhouGuangdong, China
    962.2×
  80. 77León de los AldamaGuanajuato, Mexico
    962.2×
  81. 77San Pedro de la PazBiobio, Chile
    962.2×
  82. 82Saint PaulMinnesota, United States
    952.2×
  83. 83CasperWyoming, United States
    952.2×
  84. 84Khlong Sam WaBangkok, Thailand
    952.2×
  85. 85Udon ThaniUdon Thani, Thailand
    952.2×
  86. 85Nong KhaemBangkok, Thailand
    952.2×
  87. 85Buri RamBuriram, Thailand
    952.2×
  88. 88PhraePhrae, Thailand
    942.1×
  89. 89Ban Samae DamBangkok, Thailand
    942.1×
  90. 89Lak SiBangkok, Thailand
    942.1×
  91. 91AntananarivoAnalamanga, Madagascar
    932.1×
  92. 92Addis AbabaAddis Ababa, Ethiopia
    932.1×
  93. 92LampangLampang, Thailand
    932.1×
  94. 92Chai NatChai Nat, Thailand
    932.1×
  95. 92RabinalBaja Verapaz, Guatemala
    932.1×
  96. 92Guatemala CityGuatemala, Guatemala
    932.1×
  97. 97PhayaoPhayao, Thailand
    922.1×
  98. 97Khon KaenKhon Kaen, Thailand
    922.1×
  99. 97Silao de la VictoriaGuanajuato, Mexico
    922.1×
  100. 97Great FallsMontana, United States
    922.1×
  101. 101OmahaNebraska, United States
    922.1×
  102. 101AirdrieAlberta, Canada
    922.1×
  103. 103ChiguayanteBiobio, Chile
    922.1×
  104. 104Puerto MonttLos Lagos Region, Chile
    922.1×
  105. 105Mae SotTak, Thailand
    912.1×
  106. 106Puerto AysénAysén, Chile
    912.0×
  107. 107Ban HouakhouaBokeo, Laos
    902.0×
  108. 108ValdiviaLos Ríos Region, Chile
    902.0×
  109. 109Phra Nakhon Si AyutthayaPhra Nakhon Si Ayutthaya, Thailand
    902.0×
  110. 109Saphan SungBangkok, Thailand
    902.0×
  111. 111Suphan BuriSuphan Buri, Thailand
    892.0×
  112. 112Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    892.0×
  113. 113LincolnNebraska, United States
    892.0×
  114. 114Chiang RaiChiang Rai, Thailand
    881.9×
  115. 114Wan ChaiWan Chai, Hong Kong
    881.9×
  116. 114QuinteroValparaiso, Chile
    881.9×
  117. 114MissoulaMontana, United States
    881.9×
  118. 118Kathmandulow-cost sensorsBagmati Province, Nepal
    881.9×
  119. 118ChaiyaphumChaiyaphum, Thailand
    881.9×
  120. 118CheyenneWyoming, United States
    881.9×
  121. 118Lat KrabangBangkok, Thailand
    881.9×
  122. 122TocopillaAntofagasta, Chile
    881.9×
  123. 123TemucoAraucania, Chile
    871.9×
  124. 124ThembisaGauteng, South Africa
    871.9×
  125. 124Sakon NakhonSakon Nakhon, Thailand
    871.9×
  126. 124Bang KapiBangkok, Thailand
    871.9×
  127. 127Sing BuriSing Buri, Thailand
    861.9×
  128. 127CoyhaiqueAysén, Chile
    861.9×
  129. 129LamphunLamphun, Thailand
    861.9×
  130. 129Khlong LuangPathum Thani, Thailand
    861.9×
  131. 129RochesterMinnesota, United States
    861.9×
  132. 132BangkokBangkok, Thailand
    861.9×
  133. 132PentictonBritish Columbia, Canada
    861.9×
  134. 134Nakhon SawanNakhon Sawan, Thailand
    861.8×
  135. 135Samut PrakanSamut Prakan, Thailand
    851.8×
  136. 136GuanajuatoGuanajuato, Mexico
    851.8×
  137. 137Bueng KumBangkok, Thailand
    851.8×
  138. 138Nong ChokBangkok, Thailand
    841.8×
  139. 138Swift CurrentSaskatchewan, Canada
    841.8×
  140. 140Chiang MaiChiang Mai, Thailand
    841.8×
  141. 140Phra PradaengSamut Prakan, Thailand
    841.8×
  142. 142RayongRayong, Thailand
    831.8×
  143. 142PhichitPhichit, Thailand
    831.8×
  144. 144Kamphaeng PhetKamphaeng Phet, Thailand
    831.7×
  145. 145QuillotaValparaiso, Chile
    821.7×
  146. 145Sai MaiBangkok, Thailand
    821.7×
  147. 147Ban Talat BuengChon Buri, Thailand
    821.7×
  148. 147RexburgIdaho, United States
    821.7×
  149. 149RatchaburiRatchaburi, Thailand
    811.7×
  150. 150Puente AltoSantiago Metropolitan, Chile
    811.7×
  151. 151BlaineMinnesota, United States
    811.7×
  152. 152ChennaiTamil Nadu, India
    811.7×
  153. 152Mueang NonthaburiNonthaburi, Thailand
    811.7×
  154. 154Bang Bo DistrictSamut Prakan, Thailand
    801.7×
  155. 155Şabāḩ as SālimMubārak al Kabīr, Kuwait
    801.7×
  156. 156LotaBiobio, Chile
    801.6×
  157. 157SukhothaiSukhothai, Thailand
    801.6×
  158. 158AricaArica y Parinacota Region, Chile
    801.6×
  159. 159AranyaprathetSa Kaeo, Thailand
    791.6×
  160. 159IrapuatoGuanajuato, Mexico
    791.6×
  161. 159SquamishBritish Columbia, Canada
    791.6×
  162. 162Nakhon PathomNakhon Pathom, Thailand
    791.6×
  163. 163Samut SakhonSamut Sakhon, Thailand
    791.6×
  164. 163Ban Khlong PrawetBangkok, Thailand
    791.6×
  165. 163Sau Mau PingKwun Tong District, Hong Kong
    791.6×
  166. 166Laem ChabangChon Buri, Thailand
    781.6×
  167. 167Ban ChangRayong, Thailand
    781.6×
  168. 167CoquimboCoquimbo Region, Chile
    781.6×
  169. 167LewistonIdaho, United States
    781.6×
  170. 170Islamabadlow-cost sensorsIslamabad, Pakistan
    771.5×
  171. 170Alto HospicioTarapacá, Chile
    771.5×
  172. 172LethbridgeAlberta, Canada
    761.5×
  173. 173PullmanWashington, United States
    761.5×
  174. 174Mexico CityMexico City, Mexico
    761.5×
  175. 174DuluthMinnesota, United States
    761.5×
  176. 176KolkataWest Bengal, India
    751.5×
  177. 177BritsNorth West, South Africa
    751.5×
  178. 178SuperiorWisconsin, United States
    751.5×
  179. 179AntofagastaAntofagasta, Chile
    741.4×
  180. 180ChanthaburiChanthaburi, Thailand
    741.4×
  181. 180Naucalpan de JuárezMéxico, Mexico
    741.4×
  182. 182MoscowIdaho, United States
    741.4×
  183. 183La SerenaCoquimbo Region, Chile
    741.4×
  184. 183ConcónValparaiso, Chile
    741.4×
  185. 185MiddelburgMpumalanga, South Africa
    731.4×
  186. 185TratTrat, Thailand
    731.4×
  187. 187ColomboWestern Province, Sri Lanka
    731.4×
  188. 188DushanbeDushanbe, Tajikistan
    731.4×
  189. 188YangonYangon, Myanmar
    731.4×
  190. 188Viña del MarValparaiso, Chile
    731.4×
  191. 191HavířovMoravian-Silesian Region, Czechia
    721.4×
  192. 192Hua HinPrachuap Khiri Khan, Thailand
    721.4×
  193. 193Tsuen WanTsuen Wan, Hong Kong
    721.4×
  194. 193FanlingNorth District, Hong Kong
    721.4×
  195. 193EdmontonAlberta, Canada
    721.4×
  196. 196SalorTashkent Region, Uzbekistan
    721.4×
  197. 197AbasoloGuanajuato, Mexico
    711.3×
  198. 198Mong KokYau Tsim Mong District, Hong Kong
    711.3×
  199. 198San Miguel de AllendeGuanajuato, Mexico
    711.3×
  200. 198BendOregon, United States
    711.3×

Top 200 of 1,569 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, May 18, 2023, smogrank.com/history/2023-05-18 (accessed 2 Oct 2026).

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