Most polluted city in the world: Delhi consistently ranks among the top 3

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. Air pollution remains one of the most pressing environmental challenges of the 21st century, affecting millions of people around the world . The world ’s most polluted cities often face a combination of rapid urbanisation and limited air quality regulations. These conditions contribute to severe health risks, including respiratory and cardiovascular diseases. According to the data of IQAir, here are the top 10 most polluted cities in the world in the year 2025: (Note: AQI⁺ US: 0-50 Good ... Keep track of the most polluted cities in the world with our air quality index (AQI) ranking. The 2025 World Air Quality Report by IQAir has not been published yet. However, real-time rankings of the most polluted major cities are currently shown on the IQAir website.