Hindustan Times, New Delhi

Vehicles ply at Vijay Chowk amid low visibility, in New Delhi. (File photo)



Delhi’s air quality continued to remain in the very poor category on Friday morning. At 7am, the air quality index (AQI) was 335, as per the Central Pollution Control Board (CPCB). The average AQI on Thursday was 341.

However, government agencies have forecast a deterioration in air quality from December 4 onwards, as wind speed is going to reduce and turn calm around December 6-7, and may plunge further. At the same time, a change is likely in wind pattern from north-westerly to easterly, which may bring moisture allowing accumulation of pollutants close to the ground.

Also, shallow fog in the morning is expected on December 4-5.

On a scale of 0 to 500, an AQI value between 300 and 400 is considered very poor, and that above 400 is considered severe.

According to India Meteorological Department (IMD), the air is likely to remain in the very poor zone on Friday, but from Saturday, wind speed will slow down and there will be further deterioration of air quality. IMD scientists warned that on December 6 and December 7, the AQI might even slip to the severe zone.

“Our forecast says that on December 6 and December 7, the air quality will be at its worst and is even likely to slip into the latter end of very poor or severe,” a senior IMD scientist said.

He added that the change in wind direction is due to a western disturbance that will affect Jammu and Kashmir and Himachal Pradesh from the night of December 3, which will also have an impact on Delhi. “Whenever there is a change in wind pattern, winds turn calm and trap pollutants close to the ground,” he said.

On Thursday, the minimum temperature settled at 8.2 degrees Celsius, a notch below normal. The maximum was 27.2, two notches above normal.