SmogRank / History / January 31, 2024

Most polluted cities on January 31, 2024

1,950 cities ranked by their average PM2.5 over the day; the worst was N'Djamena, Chad, at 297.0 µg/m³. Each city's own local calendar day.

Bad-air episodes during January 31, 2024. All episodes.

← N'Djamena 297.0 µg/m³ 200 µg/m³15 WHO 24-hour guideline
Every city ranked for January 31, 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
    44319.8×
  2. 2DelhiDelhi, India
    35616.9×
  3. 3Dhakalow-cost sensorsDhaka Division, Bangladesh
    29314.5×
  4. 4Peshawarlow-cost sensorsKhyber Pakhtunkhwa, Pakistan
    22610.1×
  5. 5Banja LukaSrpska, Bosnia and Herzegovina
    2098.9×
  6. 6Ulan BatorUlaanbaatar, Mongolia
    2008.3×
  7. 7PljevljaPljevlja, Montenegro
    1917.5×
  8. 8KourouGuyane, French Guiana
    1877.1×
  9. 9Kathmandulow-cost sensorsBagmati Province, Nepal
    1867.1×
  10. 10Novi PazarCentral Serbia, Serbia
    1846.9×
  11. 11KolkataWest Bengal, India
    1826.7×
  12. 12HanoiHanoi, Vietnam
    1816.5×
  13. 13Abujalow-cost sensorsFCT, Nigeria
    1806.5×
  14. 14SarajevoFederation of B&H, Bosnia and Herzegovina
    1786.2×
  15. 15CayenneGuyane, French Guiana
    1756.0×
  16. 16PančevoVojvodina, Serbia
    1745.9×
  17. 17LazarevacCentral Serbia, Serbia
    1745.9×
  18. 18UžiceCentral Serbia, Serbia
    1725.7×
  19. 19ObrenovacCentral Serbia, Serbia
    1725.7×
  20. 20PodgoricaPodgorica, Montenegro
    1705.5×
  21. 21SmederevoCentral Serbia, Serbia
    1685.3×
  22. 22DejCluj County, Romania
    1675.2×
  23. 23CapannoriTuscany, Italy
    1665.1×
  24. 24KavadarciKavadarci, North Macedonia
    1655.0×
  25. 25NišCentral Serbia, Serbia
    1624.8×
  26. 26ZemunCentral Serbia, Serbia
    1624.8×
  27. 27SkopjeGrad Skopje, North Macedonia
    1624.7×
  28. 28BelgradeCentral Serbia, Serbia
    1624.7×
  29. 28OpoleOpole Voivodeship, Poland
    1624.7×
  30. 30KanchanaburiKanchanaburi, Thailand
    1614.6×
  31. 31TetovoTetovo, North Macedonia
    1604.6×
  32. 32Nong KhaemBangkok, Thailand
    1594.5×
  33. 33Bang NaBangkok, Thailand
    1594.5×
  34. 34Almatylow-cost sensorsAlmaty, Kazakhstan
    1584.4×
  35. 35MumbaiMaharashtra, India
    1584.3×
  36. 35Khlong Sam WaBangkok, Thailand
    1584.3×
  37. 37MiskolcBorsod-Abaúj-Zemplén, Hungary
    1574.3×
  38. 38Ban Samae DamBangkok, Thailand
    1574.3×
  39. 39GuangzhouGuangdong, China
    1574.3×
  40. 40AranyaprathetSa Kaeo, Thailand
    1564.2×
  41. 41Lat KrabangBangkok, Thailand
    1564.2×
  42. 42Lak SiBangkok, Thailand
    1564.2×
  43. 43Bang KapiBangkok, Thailand
    1554.1×
  44. 44Bang Khun ThianBangkok, Thailand
    1554.1×
  45. 45Samut SakhonSamut Sakhon, Thailand
    1554.1×
  46. 46BangkokBangkok, Thailand
    1554.1×
  47. 47Mueang NonthaburiNonthaburi, Thailand
    1554.0×
  48. 48StrumicaStrumica, North Macedonia
    1544.0×
  49. 48Ban Khlong PrawetBangkok, Thailand
    1544.0×
  50. 50Nong ChokBangkok, Thailand
    1544.0×
  51. 51Bueng KumBangkok, Thailand
    1544.0×
  52. 52Khlong LuangPathum Thani, Thailand
    1543.9×
  53. 53Khan Na YaoBangkok, Thailand
    1533.9×
  54. 54Saphan SungBangkok, Thailand
    1533.9×
  55. 55RatchaburiRatchaburi, Thailand
    1523.8×
  56. 56Cluj-NapocaCluj County, Romania
    1523.8×
  57. 57Bang Bo DistrictSamut Prakan, Thailand
    1513.7×
  58. 58LučenecBanská Bystrica Region, Slovakia
    1513.7×
  59. 59PaviaLombardy, Italy
    1513.7×
  60. 60KazincbarcikaBorsod-Abaúj-Zemplén, Hungary
    1493.7×
  61. 61DěčínÚstí nad Labem Region, Czechia
    1483.6×
  62. 62Sai MaiBangkok, Thailand
    1463.6×
  63. 63SremčicaCentral Serbia, Serbia
    1463.6×
  64. 64Phra PradaengSamut Prakan, Thailand
    1463.6×
  65. 65BitolaBitola, North Macedonia
    1423.5×
  66. 65LitvínovÚstí nad Labem Region, Czechia
    1423.5×
  67. 67KrakówLesser Poland, Poland
    1423.5×
  68. 68Samut PrakanSamut Prakan, Thailand
    1413.5×
  69. 69BeijingBeijing, China
    1413.4×
  70. 70Nakhon RatchasimaNakhon Ratchasima, Thailand
    1403.4×
  71. 71RužomberokŽilina Region, Slovakia
    1393.4×
  72. 72Ubon RatchathaniUbon Ratchathani, Thailand
    1383.4×
  73. 73IaşiIași County, Romania
    1373.4×
  74. 74VigevanoLombardy, Italy
    1373.3×
  75. 75AcerraCampania, Italy
    1363.3×
  76. 76MartinŽilina Region, Slovakia
    1363.3×
  77. 77MilanLombardy, Italy
    1343.3×
  78. 78SurinSurin, Thailand
    1343.2×
  79. 79Nakhon PathomNakhon Pathom, Thailand
    1333.2×
  80. 80TepliceÚstí nad Labem Region, Czechia
    1333.2×
  81. 81Phra Nakhon Si AyutthayaPhra Nakhon Si Ayutthaya, Thailand
    1323.2×
  82. 82KigaliKigali, Rwanda
    1323.2×
  83. 82Laem ChabangChon Buri, Thailand
    1323.2×
  84. 84Novi SadVojvodina, Serbia
    1313.2×
  85. 85HyderabadTelangana, India
    1303.2×
  86. 86SaraburiSaraburi, Thailand
    1303.1×
  87. 87PúchovTrenčín Region, Slovakia
    1283.1×
  88. 88OlomoucOlomouc Region, Czechia
    1283.1×
  89. 89FutogVojvodina, Serbia
    1273.1×
  90. 90PezinokBratislava Region, Slovakia
    1273.1×
  91. 91BeneventoCampania, Italy
    1273.1×
  92. 92GrazStyria, Austria
    1263.0×
  93. 93Vranov nad TopľouPrešov Region, Slovakia
    1253.0×
  94. 93DziałdowoWarmia-Masuria, Poland
    1253.0×
  95. 93Lop BuriLopburi, Thailand
    1253.0×
  96. 93MostÚstí nad Labem Region, Czechia
    1253.0×
  97. 97PuertollanoCastille-La Mancha, Spain
    1253.0×
  98. 97PardubicePardubice Region, Czechia
    1253.0×
  99. 99TratTrat, Thailand
    1253.0×
  100. 99Sing BuriSing Buri, Thailand
    1253.0×
  101. 101ShenyangLiaoning, China
    1243.0×
  102. 102AugustówPodlasie, Poland
    1243.0×
  103. 102Buri RamBuriram, Thailand
    1243.0×
  104. 104BraPiedmont, Italy
    1243.0×
  105. 105Nakhon NayokNakhon Nayok, Thailand
    1233.0×
  106. 106Chai NatChai Nat, Thailand
    1222.9×
  107. 107CairoCairo, Egypt
    1222.9×
  108. 108Mladá BoleslavCentral Bohemia, Czechia
    1222.9×
  109. 108KladnoCentral Bohemia, Czechia
    1222.9×
  110. 108PesaroThe Marches, Italy
    1222.9×
  111. 111Kampalalow-cost sensorsCentral Region, Uganda
    1212.9×
  112. 111ChaiyaphumChaiyaphum, Thailand
    1212.9×
  113. 113Suphan BuriSuphan Buri, Thailand
    1212.9×
  114. 114BerounCentral Bohemia, Czechia
    1212.9×
  115. 115KalasinKalasin, Thailand
    1202.9×
  116. 115Hradec KrálovéHradec Králové Region, Czechia
    1202.9×
  117. 115LodiLombardy, Italy
    1202.9×
  118. 118ZnojmoSouth Moravian, Czechia
    1202.9×
  119. 119GostivarGostivar, North Macedonia
    1192.8×
  120. 120PraguePrague, Czechia
    1182.8×
  121. 121PrešovPrešov Region, Slovakia
    1182.8×
  122. 122IngolstadtBavaria, Germany
    1182.8×
  123. 123NovaraPiedmont, Italy
    1172.8×
  124. 124AlgiersAlgiers, Algeria
    1172.8×
  125. 125YasothonYasothon, Thailand
    1172.8×
  126. 125Si Sa KetSi Sa Ket, Thailand
    1172.8×
  127. 125MantuaLombardy, Italy
    1172.8×
  128. 128Bielsko-BialaSilesia, Poland
    1162.8×
  129. 129DębicaSubcarpathia, Poland
    1152.7×
  130. 129MalackyBratislava Region, Slovakia
    1152.7×
  131. 131KošiceKošice Region, Slovakia
    1152.7×
  132. 132KielceŚwiętokrzyskie, Poland
    1142.7×
  133. 133Ústí nad LabemÚstí nad Labem Region, Czechia
    1142.7×
  134. 133VimercateLombardy, Italy
    1142.7×
  135. 135ĆuprijaCentral Serbia, Serbia
    1132.7×
  136. 136Liptovský Mikulᚎilina Region, Slovakia
    1132.7×
  137. 137TrenčínTrenčín Region, Slovakia
    1122.7×
  138. 138Ban ChangRayong, Thailand
    1122.7×
  139. 139NaplesCampania, Italy
    1122.7×
  140. 140ŽilinaŽilina Region, Slovakia
    1112.6×
  141. 141PhetchaburiPhetchaburi, Thailand
    1112.6×
  142. 141RacibórzSilesia, Poland
    1112.6×
  143. 141Jastrzębie ZdrójSilesia, Poland
    1112.6×
  144. 144Puerto MonttLos Lagos Region, Chile
    1102.6×
  145. 145NanNan, Thailand
    1092.6×
  146. 146HumennéPrešov Region, Slovakia
    1092.6×
  147. 146ZvolenBanská Bystrica Region, Slovakia
    1092.6×
  148. 148PhetchabunPhetchabun, Thailand
    1092.6×
  149. 149TrebišovKošice Region, Slovakia
    1092.6×
  150. 150Roi EtRoi Et, Thailand
    1082.6×
  151. 150Khon KaenKhon Kaen, Thailand
    1082.6×
  152. 150TrnavaTrnava Region, Slovakia
    1082.6×
  153. 153ErbaLombardy, Italy
    1082.6×
  154. 154Ban Talat BuengChon Buri, Thailand
    1082.5×
  155. 155VelesVeles, North Macedonia
    1072.5×
  156. 155České BudějoviceSouth Bohemian Region, Czechia
    1072.5×
  157. 157Botevgradlow-cost sensorsSofia, Bulgaria
    1062.5×
  158. 158AvignonProvence-Alpes-Côte d'Azur, France
    1062.5×
  159. 158PřerovOlomouc Region, Czechia
    1062.5×
  160. 160LinzUpper Austria, Austria
    1052.5×
  161. 160PartizánskeTrenčín Region, Slovakia
    1052.5×
  162. 160BratislavaBratislava Region, Slovakia
    1052.5×
  163. 163RayongRayong, Thailand
    1052.5×
  164. 164SenecBratislava Region, Slovakia
    1052.5×
  165. 164HandlováTrenčín Region, Slovakia
    1052.5×
  166. 166ChanthaburiChanthaburi, Thailand
    1042.5×
  167. 167KomárnoNitra Region, Slovakia
    1042.4×
  168. 168ChennaiTamil Nadu, India
    1042.4×
  169. 168AnsfeldenUpper Austria, Austria
    1042.4×
  170. 170PassauBavaria, Germany
    1032.4×
  171. 171Santa Cruz de TenerifeCanary Islands, Spain
    1032.4×
  172. 172PrievidzaTrenčín Region, Slovakia
    1022.4×
  173. 173KatowiceSilesia, Poland
    1022.4×
  174. 174Chalon-sur-SaôneBourgogne-Franche-Comté, France
    1012.4×
  175. 174KłodzkoLower Silesia, Poland
    1012.4×
  176. 176MielecSubcarpathia, Poland
    1012.4×
  177. 176Kędzierzyn-KoźleOpole Voivodeship, Poland
    1012.4×
  178. 178BardejovPrešov Region, Slovakia
    1002.4×
  179. 178Wan ChaiWan Chai, Hong Kong
    1002.4×
  180. 180ComoLombardy, Italy
    992.3×
  181. 181BrnoSouth Moravian, Czechia
    992.3×
  182. 182ČadcaŽilina Region, Slovakia
    992.3×
  183. 183TolucaMéxico, Mexico
    982.3×
  184. 184StarachowiceŚwiętokrzyskie, Poland
    982.3×
  185. 184Nakhon SawanNakhon Sawan, Thailand
    982.3×
  186. 184SereďTrnava Region, Slovakia
    982.3×
  187. 187LublinLublin, Poland
    982.3×
  188. 188ZlínZlín, Czechia
    972.3×
  189. 189DushanbeDushanbe, Tajikistan
    972.3×
  190. 190Skarżysko-KamiennaŚwiętokrzyskie, Poland
    972.3×
  191. 190MukdahanMukdahan, Thailand
    972.3×
  192. 190KlosterneuburgLower Austria, Austria
    972.3×
  193. 190VeszprémVeszprém, Hungary
    972.3×
  194. 190SenicaTrnava Region, Slovakia
    972.3×
  195. 195GyálPest County, Hungary
    972.2×
  196. 196PerchtoldsdorfLower Austria, Austria
    962.2×
  197. 196NitraNitra Region, Slovakia
    962.2×
  198. 198Romans-sur-IsèreAuvergne-Rhône-Alpes, France
    962.2×
  199. 199LyonAuvergne-Rhône-Alpes, France
    962.2×
  200. 199ŽideniceSouth Moravian, Czechia
    962.2×

Top 200 of 1,950 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, January 31, 2024, smogrank.com/history/2024-01-31 (accessed 3 Oct 2026).

Download top 10 (PNG)

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