New Delhi:

The air quality in Delhi was recorded in the 'severe' category on Thursday morning, with a marginal improvement expected just ahead of Diwali as meteorological conditions are likely to become slightly favourable.

The city's Air Quality Index (AQI) stood at 420 at 8 am on Thursday, compared to 426 at 4 pm on Wednesday. The AQI map prepared by the Central Pollution Control Board showed clusters of red dots (indicating hazardous air quality) spread across the Indo-Gangetic plains.

Neighbouring Ghaziabad (369), Gurugram (396), Noida (394), Greater Noida (450), and Faridabad (413) also reported very bad air quality.

According to officials at the India Meteorological Department, a change in wind direction from northwest to southeast due to a fresh western disturbance affecting northwest India will help reduce the contribution of smoke from stubble burning, but slow wind speed will counteract this.

However, once the western disturbance passes, the wind speed will increase from around 5-6 kmph, at present, to around 15 kmph on November 11, which will help disperse pollutants ahead of Diwali, the official said.

In view of the worsening air pollution, the Delhi government on Wednesday rescheduled the December winter break of all schools, which will now be from November 9 to November 18.