Delhi air quality worsens to poor as Diwali nears, Stage I GRAP

Delhi’s air quality deteriorated through mid‑October, moving from moderate to persistently poor levels this week as the capital and neighbouring cities of the National Capital Region prepared for Diwali, officials said. Citywide Air Quality Index readings climbed above 200 from October 14 onward, with several monitoring stations reporting very poor levels above 300 in pockets of the city.

The Central Pollution Control Board recorded Delhi’s AQI at 254 at 4 pm on October 17 and about 252 at 9 am on October 18, placing the capital in the poor category. Earlier in the week the city registered readings of about 211 on October 14 and 245 on October 16. Out of roughly 38 active monitoring stations in the city, multiple sites in northern and northeastern neighbourhoods registered very poor readings, with Anand Vihar consistently recording the highest station values. Ghaziabad, Noida and Gurugram also reported poor to very poor air on several days, keeping much of the NCR under unhealthy conditions.

Authorities and monitoring systems pointed to a mix of local emissions and regional smoke as drivers of the deterioration. Data from the Decision Support System shows transport emissions...