Delhi air quality worsens around Diwali

On 4 November, Delhi's air quality index crossed 300, entering the very poor category, as winter weather and crop residue burning worsened pollution ahead of Diwali. Authorities invoked Stage II of the Graded Response Action Plan, adding road cleaning, higher parking charges, more metro trips and staggered government office hours. The deterioration followed an unusually clean October, when Delhi recorded its lowest average AQI for the month in eight years.

On 7 November, India's top court said vehicular pollution was a major contributor to Delhi's deteriorating air quality and questioned the effectiveness of government measures. Chief Justice Surya Kant pointed to bumper-to-bumper traffic on Delhi roads and connections to the National Capital Region. The court said an AQI below 100 during winters was utopian when very poor and severe conditions had become the new normal.

On 8 November, Delhi awoke in smog after Saturday's Diwali eve had the worst air quality in 10 years. The Central Pollution Control Board said the capital had a very poor AQI of 362 on Saturday. On 9 November, smog shrouded New Delhi after Diwali firecrackers worsened seasonal pollution. The AQI exceeded 350 in several parts of the capital, reaching the severe category. Despite Supreme Court restrictions limiting fireworks to approved green firecrackers, residents lit traditional crackers, compounding pollution from vehicles and crop-residue fires.