India, Oct. 1 -- Delhi's monsoon this year turned out to be its most polluted in seven years, with the average AQI between July and September climbing to 105, the highest for the period since 2019, according to an analysis of official data. The monsoon lasted for about 84 days between July and September, and during the period the city recorded one "good" AQI day, 49 "satisfactory" days, 39 "moderate" days and two "poor" days.

The average AQI during July-September stood at 105 this year, just below the 2019 average of 106, according to the Centre for Research on Energy and Clean Air (CREA) analysis of official data. Among the two major particulate pollutants, PM10 was the more prominent pollutant this year. Its average concentration stood...