SmogRank / History / April 21, 2024

Most polluted cities on April 21, 2024

2,260 cities ranked by their average PM2.5 over the day; the worst was N'Djamena, Chad, at 112.0 µg/m³. Each city's own local calendar day.

Bad-air episodes during April 21, 2024. All episodes.

← N'Djamena 112.0 µg/m³ 100 µg/m³15 WHO 24-hour guideline
Every city ranked for April 21, 2024, 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. 1N'DjamenaN’Djaména, Chad
    1917.5×
  2. 2Kathmandulow-cost sensorsBagmati Province, Nepal
    1756.0×
  3. 3BeijingBeijing, China
    1644.9×
  4. 4Ubon RatchathaniUbon Ratchathani, Thailand
    1644.9×
  5. 5Chiang MaiChiang Mai, Thailand
    1624.7×
  6. 6KalasinKalasin, Thailand
    1614.7×
  7. 7UttaraditUttaradit, Thailand
    1614.6×
  8. 8Vientianelow-cost sensorsVientiane Prefecture, Laos
    1594.5×
  9. 9NanNan, Thailand
    1574.3×
  10. 10CoyhaiqueAysén, Chile
    1574.2×
  11. 11Mae SaiChiang Rai, Thailand
    1554.1×
  12. 12PhayaoPhayao, Thailand
    1533.9×
  13. 13RancaguaO'Higgins Region, Chile
    1533.9×
  14. 14MukdahanMukdahan, Thailand
    1523.8×
  15. 15PhetchabunPhetchabun, Thailand
    1523.8×
  16. 16RengoO'Higgins Region, Chile
    1513.7×
  17. 17Sing BuriSing Buri, Thailand
    1493.7×
  18. 18LampangLampang, Thailand
    1483.6×
  19. 19PhraePhrae, Thailand
    1463.6×
  20. 20PhichitPhichit, Thailand
    1453.6×
  21. 21CuranilahueBiobio, Chile
    1443.5×
  22. 22Udon ThaniUdon Thani, Thailand
    1433.5×
  23. 23LoeiLoei, Thailand
    1423.5×
  24. 24HanoiHanoi, Vietnam
    1423.5×
  25. 25Puerto VarasLos Lagos Region, Chile
    1413.5×
  26. 26LamphunLamphun, Thailand
    1403.4×
  27. 27Lop BuriLopburi, Thailand
    1393.4×
  28. 28HyderabadTelangana, India
    1393.4×
  29. 28Nakhon SawanNakhon Sawan, Thailand
    1393.4×
  30. 30Dhakalow-cost sensorsDhaka Division, Bangladesh
    1393.4×
  31. 30ShenyangLiaoning, China
    1393.4×
  32. 32Chiang RaiChiang Rai, Thailand
    1363.3×
  33. 33Nong Bua LamphuNong Bua Lamphu, Thailand
    1353.3×
  34. 34Sakon NakhonSakon Nakhon, Thailand
    1343.2×
  35. 35RatchaburiRatchaburi, Thailand
    1333.2×
  36. 35Khon KaenKhon Kaen, Thailand
    1333.2×
  37. 37Chai NatChai Nat, Thailand
    1323.2×
  38. 38AntananarivoAnalamanga, Madagascar
    1313.2×
  39. 39Kamphaeng PhetKamphaeng Phet, Thailand
    1303.2×
  40. 40ChaiyaphumChaiyaphum, Thailand
    1303.1×
  41. 41Phra Nakhon Si AyutthayaPhra Nakhon Si Ayutthaya, Thailand
    1293.1×
  42. 42Suphan BuriSuphan Buri, Thailand
    1293.1×
  43. 43Puente AltoSantiago Metropolitan, Chile
    1283.1×
  44. 44Nong KhaemBangkok, Thailand
    1283.1×
  45. 45SaraburiSaraburi, Thailand
    1263.0×
  46. 46Ban Samae DamBangkok, Thailand
    1263.0×
  47. 47HualpénBiobio, Chile
    1243.0×
  48. 48KanchanaburiKanchanaburi, Thailand
    1243.0×
  49. 48Bang NaBangkok, Thailand
    1243.0×
  50. 50Nakhon PathomNakhon Pathom, Thailand
    1233.0×
  51. 51Amnat CharoenAmnat Charoen, Thailand
    1222.9×
  52. 52San CarlosÑuble, Chile
    1222.9×
  53. 53Khlong Sam WaBangkok, Thailand
    1212.9×
  54. 54La UniónLos Ríos Region, Chile
    1202.9×
  55. 55Phra PradaengSamut Prakan, Thailand
    1192.9×
  56. 56CuricóMaule Region, Chile
    1192.9×
  57. 57Samut SakhonSamut Sakhon, Thailand
    1182.8×
  58. 57Santa Anita - Los FicusLima region, Peru
    1182.8×
  59. 59JakartaJakarta, Indonesia
    1182.8×
  60. 60BangkokBangkok, Thailand
    1172.8×
  61. 61CoronelBiobio, Chile
    1162.8×
  62. 62Khlong LuangPathum Thani, Thailand
    1152.8×
  63. 63Samut PrakanSamut Prakan, Thailand
    1152.7×
  64. 64PhetchaburiPhetchaburi, Thailand
    1152.7×
  65. 65SukhothaiSukhothai, Thailand
    1142.7×
  66. 66Mueang NonthaburiNonthaburi, Thailand
    1142.7×
  67. 67Nakhon RatchasimaNakhon Ratchasima, Thailand
    1142.7×
  68. 68Nong ChokBangkok, Thailand
    1132.7×
  69. 69Ban Khlong PrawetBangkok, Thailand
    1132.7×
  70. 70Roi EtRoi Et, Thailand
    1122.7×
  71. 71Bang KapiBangkok, Thailand
    1112.6×
  72. 71TemucoAraucania, Chile
    1112.6×
  73. 73HualquiBiobio, Chile
    1102.6×
  74. 74Khan Na YaoBangkok, Thailand
    1102.6×
  75. 75Lak SiBangkok, Thailand
    1092.6×
  76. 76KolkataWest Bengal, India
    1062.5×
  77. 77Nakhon NayokNakhon Nayok, Thailand
    1062.5×
  78. 78NacimientoBiobio, Chile
    1062.5×
  79. 79JeddahMecca Region, Saudi Arabia
    1052.5×
  80. 80Sai MaiBangkok, Thailand
    1032.4×
  81. 81YasothonYasothon, Thailand
    1032.4×
  82. 82RabinalBaja Verapaz, Guatemala
    1022.4×
  83. 83Bang Bo DistrictSamut Prakan, Thailand
    1022.4×
  84. 84BaghdadBaghdad, Iraq
    1012.4×
  85. 84TalcahuanoBiobio, Chile
    1012.4×
  86. 84Lat KrabangBangkok, Thailand
    1012.4×
  87. 87Hua HinPrachuap Khiri Khan, Thailand
    992.3×
  88. 87Guatemala CityGuatemala, Guatemala
    992.3×
  89. 89OsornoLos Lagos Region, Chile
    992.3×
  90. 90SantiagoSantiago Metropolitan, Chile
    982.3×
  91. 90CelayaGuanajuato, Mexico
    982.3×
  92. 92ChillánÑuble, Chile
    982.3×
  93. 93BakuBaki, Azerbaijan
    962.2×
  94. 93Abujalow-cost sensorsFCT, Nigeria
    962.2×
  95. 93TalcaMaule Region, Chile
    962.2×
  96. 96Si Maha PhotPrachin Buri, Thailand
    952.2×
  97. 96Puerto AysénAysén, Chile
    952.2×
  98. 98Mae SotTak, Thailand
    942.1×
  99. 99Laem ChabangChon Buri, Thailand
    922.1×
  100. 100QuinteroValparaiso, Chile
    922.1×
  101. 101ValdiviaLos Ríos Region, Chile
    902.0×
  102. 101QuillotaValparaiso, Chile
    902.0×
  103. 103AstanaAstana, Kazakhstan
    902.0×
  104. 104Ban ChangRayong, Thailand
    892.0×
  105. 105Si Sa KetSi Sa Ket, Thailand
    892.0×
  106. 106YangonYangon, Myanmar
    881.9×
  107. 107TalaganteSantiago Metropolitan, Chile
    881.9×
  108. 108Ban Talat BuengChon Buri, Thailand
    871.9×
  109. 108Jacobo HunterArequipa, Peru
    871.9×
  110. 110ChanthaburiChanthaburi, Thailand
    861.8×
  111. 110SarajevoFederation of B&H, Bosnia and Herzegovina
    861.8×
  112. 112DushanbeDushanbe, Tajikistan
    851.8×
  113. 113CairoCairo, Egypt
    851.8×
  114. 114ConcepciónBiobio, Chile
    841.8×
  115. 114ChiguayanteBiobio, Chile
    841.8×
  116. 116Viña del MarValparaiso, Chile
    841.8×
  117. 117Karachilow-cost sensorsSindh, Pakistan
    831.8×
  118. 118Kodamachō-kodamaminamiSaitama, Japan
    831.8×
  119. 119YoriiSaitama, Japan
    831.7×
  120. 120GotembaShizuoka, Japan
    821.7×
  121. 121ConcónValparaiso, Chile
    821.7×
  122. 122TakasakiGunma, Japan
    821.7×
  123. 122FontanaCalifornia, United States
    821.7×
  124. 122IrumaSaitama, Japan
    821.7×
  125. 125ChichibuSaitama, Japan
    821.7×
  126. 126MorohongōSaitama, Japan
    811.7×
  127. 126CauquenesMaule Region, Chile
    811.7×
  128. 128RayongRayong, Thailand
    811.7×
  129. 129AricaArica y Parinacota Region, Chile
    811.7×
  130. 130QuilpuéValparaiso, Chile
    801.7×
  131. 131AntofagastaAntofagasta, Chile
    801.7×
  132. 132Islamabadlow-cost sensorsIslamabad, Pakistan
    801.6×
  133. 132ZhushanTaiwan, Taiwan
    801.6×
  134. 132OwaseMie, Japan
    801.6×
  135. 135Addis AbabaAddis Ababa, Ethiopia
    801.6×
  136. 135ShanghaiShanghai, China
    801.6×
  137. 137TomiokaGunma, Japan
    791.6×
  138. 137MenumaSaitama, Japan
    791.6×
  139. 139KigaliKigali, Rwanda
    791.6×
  140. 139FengshanTakao, Taiwan
    791.6×
  141. 139UedaNagano, Japan
    791.6×
  142. 142KiryūGunma, Japan
    791.6×
  143. 143TatebayashiGunma, Japan
    781.6×
  144. 144AshgabatAshgabat, Turkmenistan
    781.6×
  145. 144Buri RamBuriram, Thailand
    781.6×
  146. 146Sakai-nakajimaGunma, Japan
    781.6×
  147. 146NakanojōGunma, Japan
    781.6×
  148. 148IgusaSaitama, Japan
    781.6×
  149. 149HannōSaitama, Japan
    771.6×
  150. 150SanoTochigi, Japan
    771.5×
  151. 151GyōdaSaitama, Japan
    771.5×
  152. 151Los ÁngelesBiobio, Chile
    771.5×
  153. 153KōriyamaFukushima, Japan
    771.5×
  154. 153VillarricaAraucania, Chile
    771.5×
  155. 155TaibaoTaiwan, Taiwan
    771.5×
  156. 155RiversideCalifornia, United States
    771.5×
  157. 157ShibukawaGunma, Japan
    761.5×
  158. 157HonjōSaitama, Japan
    761.5×
  159. 157AgeoSaitama, Japan
    761.5×
  160. 157Puerto MonttLos Lagos Region, Chile
    761.5×
  161. 161Novi PazarCentral Serbia, Serbia
    761.5×
  162. 161ChaozhouTaiwan, Taiwan
    761.5×
  163. 161LęborkPomerania, Poland
    761.5×
  164. 164KazoSaitama, Japan
    761.5×
  165. 164NiizaSaitama, Japan
    761.5×
  166. 164Higashi-MatsuyamaSaitama, Japan
    761.5×
  167. 167SurinSurin, Thailand
    761.5×
  168. 167Villa Poeta José Gálvez BarrenecheaLima region, Peru
    761.5×
  169. 169PattaniPattani, Thailand
    761.5×
  170. 169YongkangTaiwan, Taiwan
    761.5×
  171. 169YuanlinTaiwan, Taiwan
    761.5×
  172. 169Misato, SaitamaSaitama, Japan
    761.5×
  173. 173ErlunTaiwan, Taiwan
    751.5×
  174. 173SakadoSaitama, Japan
    751.5×
  175. 173SayamaSaitama, Japan
    751.5×
  176. 176BeigangTaiwan, Taiwan
    751.5×
  177. 176AyaseKanagawa, Japan
    751.5×
  178. 178San Pedro de la PazBiobio, Chile
    751.5×
  179. 179ErlinTaiwan, Taiwan
    751.5×
  180. 179ŌtsukiYamanashi, Japan
    751.5×
  181. 181AsakaSaitama, Japan
    741.4×
  182. 181Minami-SōmaFukushima, Japan
    741.4×
  183. 183NumataGunma, Japan
    741.4×
  184. 183NagaiYamagata, Japan
    741.4×
  185. 183AguascalientesAguascalientes, Mexico
    741.4×
  186. 186SalorTashkent Region, Uzbekistan
    741.4×
  187. 186YokotaTokyo, Japan
    741.4×
  188. 186SōmaFukushima, Japan
    741.4×
  189. 189AtamiShizuoka, Japan
    741.4×
  190. 189ShiroishiMiyagi, Japan
    741.4×
  191. 189SalamancaGuanajuato, Mexico
    741.4×
  192. 192PhuketPhuket, Thailand
    731.4×
  193. 192Hat YaiSongkhla, Thailand
    731.4×
  194. 192KaohsiungTakao, Taiwan
    731.4×
  195. 192ValjevoCentral Serbia, Serbia
    731.4×
  196. 192ChimboteAncash, Peru
    731.4×
  197. 197KumagayaSaitama, Japan
    731.4×
  198. 197KōnosuSaitama, Japan
    731.4×
  199. 197ChikumaNagano, Japan
    731.4×
  200. 200NumazuShizuoka, Japan
    731.4×

Top 200 of 2,260 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

Not covered: the government monitoring networks of China and Turkey, which publish no terms that let us reuse their readings. Most cities there are missing from this board, not clean. Why.

Use this board

SmogRank, most polluted cities, PM2.5, April 21, 2024, smogrank.com/history/2024-04-21 (accessed 3 Oct 2026).

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