SmogRank / History / May 31, 2025

Most polluted cities on May 31, 2025

2,644 cities ranked by their average PM2.5 over the day; the worst was Katihar, India, at 273.0 µg/m³. Each city's own local calendar day.

Bad-air episodes during May 31, 2025. All episodes.

← Katihar 273.0 µg/m³ 200 µg/m³15 WHO 24-hour guideline
Every city ranked for May 31, 2025, 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. 1KatiharBihar, India
    39618.2×
  2. 2ReginaSaskatchewan, Canada
    24411.3×
  3. 3Fort McMurrayAlberta, Canada
    2159.3×
  4. 4OsornoLos Lagos Region, Chile
    2028.5×
  5. 5Puerto VarasLos Lagos Region, Chile
    1957.9×
  6. 6SaskatoonSaskatchewan, Canada
    1937.7×
  7. 7LoniUttar Pradesh, India
    1917.5×
  8. 8TemucoAraucania, Chile
    1846.9×
  9. 8Prince AlbertSaskatchewan, Canada
    1846.9×
  10. 10BawānaDelhi, India
    1836.7×
  11. 11NarelaDelhi, India
    1806.5×
  12. 12VillarricaAraucania, Chile
    1786.3×
  13. 13Aya NagarDelhi, India
    1766.1×
  14. 14Puerto MonttLos Lagos Region, Chile
    1766.1×
  15. 15ValdiviaLos Ríos Region, Chile
    1735.8×
  16. 16HanumāngarhRajasthan, India
    1715.6×
  17. 17La UniónLos Ríos Region, Chile
    1705.5×
  18. 18DelhiDelhi, India
    1705.5×
  19. 19GhāziābādUttar Pradesh, India
    1685.3×
  20. 20Las CrucesNew Mexico, United States
    1685.3×
  21. 21BulandshahrUttar Pradesh, India
    1675.3×
  22. 22Santa Anita - Los FicusLima region, Peru
    1675.2×
  23. 23BhiwadiRajasthan, India
    1655.1×
  24. 24LucknowUttar Pradesh, India
    1644.9×
  25. 25JaipurRajasthan, India
    1624.7×
  26. 26NoidaUttar Pradesh, India
    1614.7×
  27. 27Dera MāndiDelhi, India
    1604.5×
  28. 28KhannaPunjab, India
    1584.4×
  29. 29HualquiBiobio, Chile
    1584.3×
  30. 30NāgaurRajasthan, India
    1584.3×
  31. 30ChandigarhChandigarh, India
    1584.3×
  32. 30AmritsarPunjab, India
    1584.3×
  33. 33Sawai MadhopurRajasthan, India
    1584.3×
  34. 34RānipetTamil Nadu, India
    1574.3×
  35. 35JaisalmerRajasthan, India
    1554.1×
  36. 36ChāpraBihar, India
    1554.1×
  37. 37GwaliorMadhya Pradesh, India
    1544.0×
  38. 37BathindaPunjab, India
    1544.0×
  39. 39HualpénBiobio, Chile
    1544.0×
  40. 40PāliRajasthan, India
    1533.9×
  41. 41NajafgarhDelhi, India
    1533.9×
  42. 42GobindgarhPunjab, India
    1533.9×
  43. 43DādriUttar Pradesh, India
    1523.8×
  44. 44UdaipurRajasthan, India
    1523.8×
  45. 45PatnaBihar, India
    1523.8×
  46. 46DausaRajasthan, India
    1513.7×
  47. 47MuzaffarnagarUttar Pradesh, India
    1513.7×
  48. 48LudhianaPunjab, India
    1453.6×
  49. 49KhurjaUttar Pradesh, India
    1443.5×
  50. 50JhunjhunūnRajasthan, India
    1413.5×
  51. 51JakartaJakarta, Indonesia
    1383.4×
  52. 52TonkRajasthan, India
    1373.3×
  53. 52CoronelBiobio, Chile
    1373.3×
  54. 54ChittorgarhRajasthan, India
    1363.3×
  55. 55MohaliPunjab, India
    1363.3×
  56. 56BhilwaraRajasthan, India
    1353.3×
  57. 57WatertownSouth Dakota, United States
    1343.3×
  58. 58RasapūdipalemAndhra Pradesh, India
    1333.2×
  59. 59KigaliKigali, Rwanda
    1313.2×
  60. 59SīkarRajasthan, India
    1313.2×
  61. 59Puente AltoSantiago Metropolitan, Chile
    1313.2×
  62. 62SantiagoSantiago Metropolitan, Chile
    1313.2×
  63. 63RamanathapuramTamil Nadu, India
    1313.2×
  64. 63TalaganteSantiago Metropolitan, Chile
    1313.2×
  65. 65RengoO'Higgins Region, Chile
    1303.2×
  66. 66KanpurUttar Pradesh, India
    1293.1×
  67. 66KanchipuramTamil Nadu, India
    1293.1×
  68. 68CuranilahueBiobio, Chile
    1283.1×
  69. 69ChūruRajasthan, India
    1283.1×
  70. 70TemeculaCalifornia, United States
    1273.1×
  71. 71GorakhpurUttar Pradesh, India
    1273.1×
  72. 72PatiālaPunjab, India
    1263.1×
  73. 73BānswāraRajasthan, India
    1253.0×
  74. 74SasarāmBihar, India
    1253.0×
  75. 75DhuleMaharashtra, India
    1253.0×
  76. 76BārmerRajasthan, India
    1243.0×
  77. 77AnantapurAndhra Pradesh, India
    1233.0×
  78. 78AhmedabadGujarat, India
    1222.9×
  79. 79RourkelaOdisha, India
    1222.9×
  80. 80LinaresMaule Region, Chile
    1182.8×
  81. 81Sunland ParkNew Mexico, United States
    1172.8×
  82. 82NagaonAssam, India
    1152.8×
  83. 83AlwarRajasthan, India
    1152.7×
  84. 84GayaBihar, India
    1152.7×
  85. 85BikanerRajasthan, India
    1142.7×
  86. 85AngulOdisha, India
    1142.7×
  87. 87KadapaAndhra Pradesh, India
    1142.7×
  88. 87BūndiRajasthan, India
    1142.7×
  89. 89Lahorelow-cost sensorsPunjab, Pakistan
    1142.7×
  90. 89TangjinChungcheongnam-do, South Korea
    1142.7×
  91. 89QuinteroValparaiso, Chile
    1142.7×
  92. 92MandideepMadhya Pradesh, India
    1142.7×
  93. 93BharatpurRajasthan, India
    1132.7×
  94. 94Hwaseong-siGyeonggi-do, South Korea
    1132.7×
  95. 95CuricóMaule Region, Chile
    1122.7×
  96. 96CoquimboCoquimbo Region, Chile
    1122.7×
  97. 96BrookingsSouth Dakota, United States
    1122.7×
  98. 98BārānRajasthan, India
    1112.6×
  99. 98RancaguaO'Higgins Region, Chile
    1112.6×
  100. 100IksanJeollabuk-do, South Korea
    1112.6×
  101. 100ByasanagarOdisha, India
    1112.6×
  102. 102AjmerRajasthan, India
    1112.6×
  103. 103RājsamandRajasthan, India
    1102.6×
  104. 104AgraUttar Pradesh, India
    1092.6×
  105. 105TalcahuanoBiobio, Chile
    1092.6×
  106. 105San Francisco De BorjaLima region, Peru
    1092.6×
  107. 107QuilpuéValparaiso, Chile
    1082.6×
  108. 108NacimientoBiobio, Chile
    1082.6×
  109. 109DūngarpurRajasthan, India
    1082.6×
  110. 110YesanChungcheongnam-do, South Korea
    1072.5×
  111. 110Ansan-siGyeonggi-do, South Korea
    1072.5×
  112. 112KarauliRajasthan, India
    1062.5×
  113. 113Sri GanganagarRajasthan, India
    1052.5×
  114. 114ChāndaMaharashtra, India
    1042.5×
  115. 115SeonghwanChungcheongnam-do, South Korea
    1042.4×
  116. 116AsanChungcheongnam-do, South Korea
    1042.4×
  117. 116Victoria de DurangoDurango, Mexico
    1042.4×
  118. 118MothīhāriBihar, India
    1022.4×
  119. 118Bucheon-siGyeonggi-do, South Korea
    1022.4×
  120. 120Goyang-siGyeonggi-do, South Korea
    1022.4×
  121. 121NagpurMaharashtra, India
    1012.4×
  122. 122SāngliMaharashtra, India
    1002.4×
  123. 123Greater NoidaUttar Pradesh, India
    1002.3×
  124. 124JalandharPunjab, India
    992.3×
  125. 125Gimpo-siGyeonggi-do, South Korea
    992.3×
  126. 125Puerto AysénAysén, Chile
    992.3×
  127. 127Dubailow-cost sensorsDubai, United Arab Emirates
    992.3×
  128. 128IncheonIncheon, South Korea
    992.3×
  129. 128AlangadKerala, India
    992.3×
  130. 130RangioraCanterbury, New Zealand
    992.3×
  131. 131KotaRajasthan, India
    982.3×
  132. 131JalorRajasthan, India
    982.3×
  133. 133GwangmyeongGyeonggi-do, South Korea
    982.3×
  134. 134PuneMaharashtra, India
    982.3×
  135. 134NandriRajasthan, India
    982.3×
  136. 136ConcónValparaiso, Chile
    972.3×
  137. 136SingrauliMadhya Pradesh, India
    972.3×
  138. 138CoimbatoreTamil Nadu, India
    972.3×
  139. 139MalegaonMaharashtra, India
    972.3×
  140. 140PithampurMadhya Pradesh, India
    962.2×
  141. 141BhelaiChhattisgarh, India
    962.2×
  142. 141BhāgalpurBihar, India
    962.2×
  143. 143DushanbeDushanbe, Tajikistan
    962.2×
  144. 143ĀsansolWest Bengal, India
    962.2×
  145. 143HongseongChungcheongnam-do, South Korea
    962.2×
  146. 143YŏnmuChungcheongnam-do, South Korea
    962.2×
  147. 143LimaLima Province, Peru
    962.2×
  148. 143VapiGujarat, India
    962.2×
  149. 149TirupatiAndhra Pradesh, India
    962.2×
  150. 149WanjuJeollabuk-do, South Korea
    962.2×
  151. 151BhiwandiMaharashtra, India
    962.2×
  152. 152HāpurUttar Pradesh, India
    952.2×
  153. 153OsanGyeonggi-do, South Korea
    952.2×
  154. 154DhaulpurRajasthan, India
    952.2×
  155. 155VijayawadaAndhra Pradesh, India
    952.2×
  156. 155TuxtlaChiapas, Mexico
    952.2×
  157. 157DamyangJeollanam-do, South Korea
    942.2×
  158. 158NashikMaharashtra, India
    942.1×
  159. 158PrayagrajUttar Pradesh, India
    942.1×
  160. 158Dera Colliery TownshipOdisha, India
    942.1×
  161. 161JeongeupJeollabuk-do, South Korea
    942.1×
  162. 162PyeongtaekGyeonggi-do, South Korea
    942.1×
  163. 163MeerutUttar Pradesh, India
    932.1×
  164. 163JabalpurMadhya Pradesh, India
    932.1×
  165. 165SuwonGyeonggi-do, South Korea
    932.1×
  166. 166NamsaJeollabuk-do, South Korea
    932.1×
  167. 167KolkataWest Bengal, India
    932.1×
  168. 167Ganghwa-gunIncheon, South Korea
    932.1×
  169. 169ThāneMaharashtra, India
    932.1×
  170. 169GunsanJeollabuk-do, South Korea
    932.1×
  171. 169ShenyangLiaoning, China
    932.1×
  172. 172Anyang-siGyeonggi-do, South Korea
    932.1×
  173. 172La SerenaCoquimbo Region, Chile
    932.1×
  174. 174DamohMadhya Pradesh, India
    922.1×
  175. 175GandhinagarGujarat, India
    922.1×
  176. 176IndoreMadhya Pradesh, India
    922.1×
  177. 176BuanJeollabuk-do, South Korea
    922.1×
  178. 176Wake Forestlow-cost sensorsNorth Carolina, United States
    922.1×
  179. 179SaugorMadhya Pradesh, India
    912.1×
  180. 180LaturMaharashtra, India
    912.0×
  181. 180BuxarBihar, India
    912.0×
  182. 182GummidipundiTamil Nadu, India
    912.0×
  183. 182JodaOdisha, India
    912.0×
  184. 184NalbāriAssam, India
    912.0×
  185. 185ConcepciónBiobio, Chile
    902.0×
  186. 186BegusaraiBihar, India
    902.0×
  187. 186SeosanChungcheongnam-do, South Korea
    902.0×
  188. 186CholulaPuebla, Mexico
    902.0×
  189. 189ArāriaBihar, India
    902.0×
  190. 189BoryeongChungcheongnam-do, South Korea
    902.0×
  191. 189NajuJeollanam-do, South Korea
    902.0×
  192. 192HyderabadTelangana, India
    902.0×
  193. 193AmaravatiAndhra Pradesh, India
    902.0×
  194. 194KalyānMaharashtra, India
    892.0×
  195. 194JodhpurRajasthan, India
    892.0×
  196. 196AkolaMaharashtra, India
    892.0×
  197. 197SibsāgarAssam, India
    892.0×
  198. 197AurangabadMaharashtra, India
    892.0×
  199. 197CauquenesMaule Region, Chile
    892.0×
  200. 200Le LamentinMartinique, Martinique
    892.0×

Top 200 of 2,644 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, May 31, 2025, smogrank.com/history/2025-05-31 (accessed 3 Oct 2026).

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