Delhi-NCR air remains hazardous after Diwali

Delhi and adjoining National Capital Region woke to hazardous air quality a day after Diwali, with widespread fireworks, local emissions and stagnant weather driving concentrations of fine particulates to levels health authorities called dangerous. Central Pollution Control Board data showed most monitoring stations in the red zone on Tuesday and Wednesday, with citywide 24 hour averages in the very poor to severe range and multiple sites recording hourly readings above 400 on the CPCB scale.

Hourly and station readings varied, but authorities said 36 of 38 Delhi monitors reported very poor to severe air on Diwali night, with Dwarka, Wazirpur, Ashok Vihar and Anand Vihar among locations exceeding the severe threshold. An independent analysis of five years of festival-period data by a climate research group found PM2.5 concentrations averaged about 488 micrograms per cubic metre in the immediate post‑Diwali period in 2025 and peaked near 675 micrograms per cubic metre late on the night of October 20. Meteorological conditions including light winds and a rapid temperature drop that created an inversion layer limited dispersion, compounding pollutant buildup.