New delhi: The air quality here remained in the "very poor" category on Thursday as experts in government agencies said it might enter "severe" levels on Diwali night, considering firecracker emissions and meteorological conditions. A change in the wind direction from northwesterly to north-north easterly was the reason behind the dip in pollution levels as it reduced the contribution of stubble burning significantly, they said.
The city recorded a 24-hour average air quality index (AQI) of 314. It was 344 on Wednesday and 476 on Tuesday. The neighbouring cities of Faridabad (304), Ghaziabad (328), Noida (305), Greater Noida (327), and Gurgaon (293), which fall in the National Capital Region (NCR), also recorded their AQI in the "poor" and "very poor" categories.
An official of the India Meteorological Department (IMD) said the "situation is much better compared to Tuesday", however, adding that the air quality is likely to deteriorate marginally on Friday.
Further, a fresh western disturbance is likely to increase the wind speed and improve the air quality in Delhi-NCR post-Diwali, the IMD said.
Light rain is likely on Sunday under the influence of a western disturbance. It is still to be seen if it is enough to wash away pollutants, Kuldeep Srivastava, the head of the IMD's regional forecasting centre said.
The IMD said winds were calm in the morning, and the minimum temperature was 11.6 degrees Celsius on Thursday.
V K Soni, the head of the IMD's environment research centre, said calm winds and firecrackers emissions may push the air quality to the "severe" zone on Diwali night. There will be a significant improvement in air quality by November 16, Soni said.