New Delhi, Nov. 2 -- As the temperature dropped to 18 degrees Celsius on November 1, Delhi's air quality plummeted into the 'poor' category, undoing the brief respite brought by last week's rains.

Typically, low temperatures and fog slow down dispersion by trapping pollutants near the surface.

With less than a week for Diwali, the air quality is expected to worsen in the coming days, dipping into the "very poor" category by the second half of this week.

On Monday morning, the Air Quality Index (AQI) in the area around ITO was recorded at 349, 'very poor'.

The city recorded a 24-hour average AQI of 261, "poor", according to the Central Pollution Control Board (CPCB)'s bulletin, worsening over 144 points from a day earlier when it regis...