New Delhi woke to heavy post-Diwali smog on November 9 after fireworks added to an already poor seasonal air-pollution picture. Reuters reported a city air-quality index (AQI) reading of 370 at 9 a.m. local time, in India’s “very poor” band, while some areas recorded readings above 400, classified as “severe.” Associated Press separately reported that several parts of the capital exceeded 350 and described worsening haze and health risks.

Readings varied across the city

The figures describe different monitoring locations and time snapshots, rather than a single uniform reading for every neighborhood. Reuters said the Central Pollution Control Board’s city reading was 370 at 9 a.m., with many areas above 400. AP reported that monitoring stations across the capital recorded elevated levels as visibility fell beneath a gray haze.

Both reports connect the post-festival rise to firecrackers set off during Diwali, despite court restrictions limiting conventional fireworks and allowing approved lower-polluting crackers only during specified hours. Reuters reported that residents said fireworks continued late into the night. The approved “green” crackers produce fewer emissions, but AP notes they still release particulate matter.

A recurring seasonal pollution pattern

Diwali smoke arrived amid a broader winter pollution pattern. AP cited cooler temperatures, low winds and stagnant air that make it harder for pollutants to disperse, alongside crop-residue smoke drifting from neighboring states and emissions from traffic, industry and construction. Reuters also described those sources as contributors to northern India’s seasonal air-quality problem.

Reuters reported that Delhi had already imposed restrictions under a graded response plan, including a direction for schools to move classes online. The city’s air readings can change by hour and location, so the values above refer to the outlets’ reported snapshots on Monday morning, not a current live advisory. Residents should follow local authorities for updated public-health guidance.

Sources: Associated Press: New Delhi wakes to toxic smog after Diwali; Reuters: Delhi air quality deteriorates after Diwali fireworks.