India, Nov. 19 -- Delhi's air quality edged dangerously close to the 'severe' category on Wednesday, as the city woke up to a dense blanket of smog with the 24-hour rolling average AQI reaching 391 (very poor) at 8am, a sharp rise from 374 (very poor) recorded at 4pm on Tuesday.

According to air quality analysts, a dip in wind speed has led to stagnation and accumulation of pollutants, worsening conditions across the capital. A thick haze of smoke stretched across the Indo-Gangetic Plain, enveloping Delhi and merging with early-morning moisture to create a persistent layer of smog.

The Central Pollution Control Board (CPCB) classifies air as 'good' when the AQI is 50 or lower, as 'satisfactory' when it is between 51 and 100, as 'moderat...