SmogRank / History / May 20, 2023

Most polluted cities on May 20, 2023

1,556 cities ranked by their average PM2.5 over the day; the worst was Edmonton, Canada, at 309.5 µg/m³. Each city's own local calendar day.

Bad-air episodes during May 20, 2023. All episodes.

← Edmonton 309.5 µg/m³ 300 µg/m³15 WHO 24-hour guideline
Every city ranked for May 20, 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. 1EdmontonAlberta, Canada
    46820.6×
  2. 2Grande PrairieAlberta, Canada
    46120.4×
  3. 3St. AlbertAlberta, Canada
    31215.4×
  4. 4Sherwood ParkAlberta, Canada
    27913.6×
  5. 5Fort St. JohnBritish Columbia, Canada
    27113.1×
  6. 6Red DeerAlberta, Canada
    26612.7×
  7. 7AirdrieAlberta, Canada
    25912.3×
  8. 8Swift CurrentSaskatchewan, Canada
    22910.3×
  9. 9BloemfonteinFree State, South Africa
    2239.9×
  10. 10Puerto VarasLos Lagos Region, Chile
    2229.8×
  11. 11OsornoLos Lagos Region, Chile
    2048.6×
  12. 12ShenyangLiaoning, China
    1947.8×
  13. 13SaskatoonSaskatchewan, Canada
    1867.0×
  14. 14Medicine HatAlberta, Canada
    1856.9×
  15. 15Prince AlbertSaskatchewan, Canada
    1836.7×
  16. 16Lahorelow-cost sensorsPunjab, Pakistan
    1826.6×
  17. 17CalgaryAlberta, Canada
    1816.5×
  18. 18Fort McMurrayAlberta, Canada
    1776.1×
  19. 19NacimientoBiobio, Chile
    1745.9×
  20. 20HyderabadTelangana, India
    1725.7×
  21. 21Kampalalow-cost sensorsCentral Region, Uganda
    1695.4×
  22. 22CoyhaiqueAysén, Chile
    1665.1×
  23. 23JohannesburgGauteng, South Africa
    1634.8×
  24. 24CuranilahueBiobio, Chile
    1624.7×
  25. 25BeijingBeijing, China
    1604.6×
  26. 25LethbridgeAlberta, Canada
    1604.6×
  27. 27BaghdadBaghdad, Iraq
    1584.4×
  28. 28Colorado SpringsColorado, United States
    1574.2×
  29. 29La UniónLos Ríos Region, Chile
    1554.1×
  30. 30ThorntonColorado, United States
    1554.1×
  31. 31DenverColorado, United States
    1544.0×
  32. 32LongmontColorado, United States
    1543.9×
  33. 33CuricóMaule Region, Chile
    1533.9×
  34. 34ThembisaGauteng, South Africa
    1533.9×
  35. 35HualquiBiobio, Chile
    1533.9×
  36. 36RancaguaO'Higgins Region, Chile
    1523.8×
  37. 37Dhakalow-cost sensorsDhaka Division, Bangladesh
    1523.8×
  38. 38Ken CarylColorado, United States
    1523.8×
  39. 39DelhiDelhi, India
    1523.8×
  40. 40RengoO'Higgins Region, Chile
    1523.8×
  41. 41TalcahuanoBiobio, Chile
    1513.7×
  42. 42Ubon RatchathaniUbon Ratchathani, Thailand
    1513.7×
  43. 42Puerto MonttLos Lagos Region, Chile
    1513.7×
  44. 44LinaresMaule Region, Chile
    1463.6×
  45. 45PakxanBolikhamsai, Laos
    1453.6×
  46. 46SantiagoSantiago Metropolitan, Chile
    1433.5×
  47. 47HanoiHanoi, Vietnam
    1363.3×
  48. 48JakartaJakarta, Indonesia
    1363.3×
  49. 49San CarlosÑuble, Chile
    1353.3×
  50. 50TalaganteSantiago Metropolitan, Chile
    1343.3×
  51. 51MukdahanMukdahan, Thailand
    1333.2×
  52. 52ChillánÑuble, Chile
    1323.2×
  53. 53Great FallsMontana, United States
    1313.2×
  54. 54BrakpanGauteng, South Africa
    1303.1×
  55. 55TemucoAraucania, Chile
    1293.1×
  56. 56AmarilloTexas, United States
    1293.1×
  57. 57TalcaMaule Region, Chile
    1293.1×
  58. 57Los ÁngelesBiobio, Chile
    1293.1×
  59. 59Puerto AysénAysén, Chile
    1283.1×
  60. 60NanNan, Thailand
    1273.1×
  61. 61Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    1263.0×
  62. 61ValdiviaLos Ríos Region, Chile
    1263.0×
  63. 63GreeleyColorado, United States
    1243.0×
  64. 64PhetchabunPhetchabun, Thailand
    1233.0×
  65. 65Roi EtRoi Et, Thailand
    1233.0×
  66. 66ChiguayanteBiobio, Chile
    1212.9×
  67. 67QuillotaValparaiso, Chile
    1192.9×
  68. 68Khon KaenKhon Kaen, Thailand
    1182.8×
  69. 69Puente AltoSantiago Metropolitan, Chile
    1172.8×
  70. 70CoronelBiobio, Chile
    1162.8×
  71. 71KigaliKigali, Rwanda
    1142.7×
  72. 72ToméBiobio, Chile
    1132.7×
  73. 73Nakhon RatchasimaNakhon Ratchasima, Thailand
    1122.7×
  74. 74AntananarivoAnalamanga, Madagascar
    1122.7×
  75. 75Udon ThaniUdon Thani, Thailand
    1102.6×
  76. 75Si Maha PhotPrachin Buri, Thailand
    1102.6×
  77. 77QuinteroValparaiso, Chile
    1102.6×
  78. 78Si Sa KetSi Sa Ket, Thailand
    1082.6×
  79. 79UttaraditUttaradit, Thailand
    1062.5×
  80. 80BritsNorth West, South Africa
    1062.5×
  81. 81Mae SaiChiang Rai, Thailand
    1062.5×
  82. 82Sakon NakhonSakon Nakhon, Thailand
    1052.5×
  83. 83BoulderColorado, United States
    1052.5×
  84. 84PhraePhrae, Thailand
    1042.5×
  85. 85ConcepciónBiobio, Chile
    1032.4×
  86. 86HobbsNew Mexico, United States
    1032.4×
  87. 87CelayaGuanajuato, Mexico
    1022.4×
  88. 88Lop BuriLopburi, Thailand
    1022.4×
  89. 89San Pedro de la PazBiobio, Chile
    1022.4×
  90. 90Viña del MarValparaiso, Chile
    1012.4×
  91. 91ChaiyaphumChaiyaphum, Thailand
    1002.4×
  92. 92Buri RamBuriram, Thailand
    1002.3×
  93. 93Mae SotTak, Thailand
    992.3×
  94. 93CheyenneWyoming, United States
    992.3×
  95. 95Nakhon SawanNakhon Sawan, Thailand
    992.3×
  96. 96PhayaoPhayao, Thailand
    992.3×
  97. 96SaraburiSaraburi, Thailand
    992.3×
  98. 98Ban HouakhouaBokeo, Laos
    992.3×
  99. 98HelenaMontana, United States
    992.3×
  100. 100CoquimboCoquimbo Region, Chile
    982.3×
  101. 101Chai NatChai Nat, Thailand
    972.3×
  102. 102ConcónValparaiso, Chile
    972.2×
  103. 103Bang NaBangkok, Thailand
    972.2×
  104. 104Fort CollinsColorado, United States
    962.2×
  105. 105GuangzhouGuangdong, China
    962.2×
  106. 106La SerenaCoquimbo Region, Chile
    962.2×
  107. 107Khlong Sam WaBangkok, Thailand
    952.2×
  108. 108Lak SiBangkok, Thailand
    942.1×
  109. 109Chiang RaiChiang Rai, Thailand
    942.1×
  110. 110Addis AbabaAddis Ababa, Ethiopia
    932.1×
  111. 111Islamabadlow-cost sensorsIslamabad, Pakistan
    922.1×
  112. 112LampangLampang, Thailand
    922.1×
  113. 112LoeiLoei, Thailand
    922.1×
  114. 114Phra Nakhon Si AyutthayaPhra Nakhon Si Ayutthaya, Thailand
    922.1×
  115. 115Nong KhaemBangkok, Thailand
    922.1×
  116. 115Khan Na YaoBangkok, Thailand
    922.1×
  117. 117Sing BuriSing Buri, Thailand
    922.1×
  118. 118PhichitPhichit, Thailand
    912.0×
  119. 119LotaBiobio, Chile
    912.0×
  120. 120LamphunLamphun, Thailand
    902.0×
  121. 120LubbockTexas, United States
    902.0×
  122. 122Chiang MaiChiang Mai, Thailand
    892.0×
  123. 122CauquenesMaule Region, Chile
    892.0×
  124. 124RayongRayong, Thailand
    892.0×
  125. 125Khlong LuangPathum Thani, Thailand
    892.0×
  126. 125ReginaSaskatchewan, Canada
    892.0×
  127. 127Bang KapiBangkok, Thailand
    881.9×
  128. 127RabinalBaja Verapaz, Guatemala
    881.9×
  129. 127Guatemala CityGuatemala, Guatemala
    881.9×
  130. 130Ban Talat BuengChon Buri, Thailand
    881.9×
  131. 131MielecSubcarpathia, Poland
    881.9×
  132. 131Lat KrabangBangkok, Thailand
    881.9×
  133. 133SukhothaiSukhothai, Thailand
    871.9×
  134. 134VereenigingGauteng, South Africa
    871.9×
  135. 135HernandoMississippi, United States
    851.8×
  136. 136Kamphaeng PhetKamphaeng Phet, Thailand
    851.8×
  137. 137Nong ChokBangkok, Thailand
    851.8×
  138. 138TakTak, Thailand
    851.8×
  139. 139RatchaburiRatchaburi, Thailand
    851.8×
  140. 139Phra PradaengSamut Prakan, Thailand
    851.8×
  141. 139Bueng KumBangkok, Thailand
    851.8×
  142. 142TratTrat, Thailand
    851.8×
  143. 143BangkokBangkok, Thailand
    841.8×
  144. 143JeffersontownKentucky, United States
    841.8×
  145. 143Idaho FallsIdaho, United States
    841.8×
  146. 146Kathmandulow-cost sensorsBagmati Province, Nepal
    841.8×
  147. 147AranyaprathetSa Kaeo, Thailand
    841.8×
  148. 147JeffersonvilleIndiana, United States
    841.8×
  149. 149Ban ChangRayong, Thailand
    841.8×
  150. 149Salt Lake CityUtah, United States
    841.8×
  151. 151Suphan BuriSuphan Buri, Thailand
    841.8×
  152. 152Bang Bo DistrictSamut Prakan, Thailand
    831.8×
  153. 153DushanbeDushanbe, Tajikistan
    831.8×
  154. 154ChennaiTamil Nadu, India
    831.7×
  155. 154LewistonIdaho, United States
    831.7×
  156. 156StilfonteinNorth West, South Africa
    831.7×
  157. 157Laem ChabangChon Buri, Thailand
    821.7×
  158. 158OpavaMoravian-Silesian Region, Czechia
    821.7×
  159. 158BountifulUtah, United States
    821.7×
  160. 158HamiltonOntario, Canada
    821.7×
  161. 161West JordanUtah, United States
    821.7×
  162. 162Mueang NonthaburiNonthaburi, Thailand
    821.7×
  163. 162SenicaTrnava Region, Slovakia
    821.7×
  164. 162KłodzkoLower Silesia, Poland
    821.7×
  165. 165MillcreekUtah, United States
    811.7×
  166. 166Jastrzębie ZdrójSilesia, Poland
    811.7×
  167. 167Sai MaiBangkok, Thailand
    811.7×
  168. 168LouisvilleKentucky, United States
    811.7×
  169. 168MagnaUtah, United States
    811.7×
  170. 170KolkataWest Bengal, India
    811.7×
  171. 170SalorTashkent Region, Uzbekistan
    811.7×
  172. 170Spanish ForkUtah, United States
    811.7×
  173. 173ChanthaburiChanthaburi, Thailand
    801.7×
  174. 173North OgdenUtah, United States
    801.7×
  175. 175BillingsMontana, United States
    801.7×
  176. 176KaliszGreater Poland, Poland
    801.6×
  177. 177SalamancaGuanajuato, Mexico
    801.6×
  178. 178Kędzierzyn-KoźleOpole Voivodeship, Poland
    801.6×
  179. 178IndianapolisIndiana, United States
    801.6×
  180. 180Jelenia GóraLower Silesia, Poland
    791.6×
  181. 180OdessaTexas, United States
    791.6×
  182. 180BozemanMontana, United States
    791.6×
  183. 183Saint MatthewsKentucky, United States
    791.6×
  184. 183WarrenOhio, United States
    791.6×
  185. 185Valley StationKentucky, United States
    791.6×
  186. 186RacibórzSilesia, Poland
    781.6×
  187. 187Ban Khlong PrawetBangkok, Thailand
    781.6×
  188. 188Samut SakhonSamut Sakhon, Thailand
    781.6×
  189. 188KrakówLesser Poland, Poland
    781.6×
  190. 190TocopillaAntofagasta, Chile
    771.6×
  191. 190OremUtah, United States
    771.6×
  192. 192Nakhon PathomNakhon Pathom, Thailand
    771.5×
  193. 193ElizabethtownKentucky, United States
    771.5×
  194. 193Fort ThomasKentucky, United States
    771.5×
  195. 193Rapid CitySouth Dakota, United States
    771.5×
  196. 196PaducahKentucky, United States
    771.5×
  197. 197Banja LukaSrpska, Bosnia and Herzegovina
    771.5×
  198. 198BloomingtonIndiana, United States
    761.5×
  199. 198EvansvilleIndiana, United States
    761.5×
  200. 200OwensboroKentucky, United States
    761.5×

Top 200 of 1,556 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

Use this board

SmogRank, most polluted cities, PM2.5, May 20, 2023, smogrank.com/history/2023-05-20 (accessed 2 Oct 2026).

Download top 10 (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms.