List of most - polluted cities by particulate matter concentration This list contains the top 500 cities by PM2.5 annual mean concentration measurement as documented by the World Health Organization covering the period from 2010 to 2022. We analyzed data published by the World Air Quality Index project and put together the 2024 updated ranking of the “25 Cities with the Worst Air Pollution in the World ”. Discover real-time top 100 most polluted cities worldwide with AQI Ranking 2025. Stay informed on global air quality at a glance. Delhi consistently ranks among the top 3 most polluted cities in the world . As of October 25, 2025, it is the most polluted city in the world , with air quality edging from unhealthy to very unhealthy, reporting levels above 186.
