What was Delhi air quality on Deepavali night?Even reading yesterday’s Diwali AQI will discomfort your lungs; check data

Delhi residents faced significant air quality issues during the Deepavali night, with the Air Quality Index reaching 370, categorized as 'very poor'. The decline in air quality followed a night of extensive firecracker bursting, exceeding the limited hours permitted by the Supreme Court. Swiss monitoring platform IQAir ranked Delhi as the third-most polluted city globally on Monday morning.

The Central Pollution Control Board classified the citywide average AQI as very poor, with numerous stations recording severe levels above 400. Worst-affected areas included Sonia Vihar (AQI 463) and Jahangirpuri (AQI 450). By Monday morning, DTU and Burari Crossing recorded AQI values of 437. The air quality was expected to worsen further, entering the severe category during the day.

Concentrations of PM2.5 spiked to 170 µg/m³, 34 times the World Health Organisation's annual guideline value. Other significant pollutants included PM10 (126 µg/m³) and carbon monoxide (1,461.5 µg/m³). Independent platform AQI.in reported a peak AQI of 2,283 immediately after Diwali, settling to a hazardous 637 by Monday morning.

Senior PM Meteorologist Navdeep Dahiya noted peak AQI levels above 1,000 between 11:30 pm and 6:30 am. Meteorological conditions, regional stubble burning, and Diwali emissions combined to exacerbate the smog. The Air Quality Early Warning System attributed the rapid decline to favorable winds and forecasted complete dispersal by the evening, with AQI expected to remain in the 'severe' category for several days.