Delhi’s AQI improves marginally but remains in very poor category

Delhi’s air quality continued to remain in the very poor category though showing a marginal improvement on Thursday morning. At 7am, the air quality index (AQI) was 345, as per the Central Pollution Control Board (CPCB). The average AQI on Wednesday was 373.

However, government agencies have forecast a deterioration in air quality from December 4 onwards, as winds are going to turn calm. 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.

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 speeds will slow down and there will be further deterioration of air quality. They warned that on December 6 and December 7, the AQI might even slip to the severe zone, scientists said.

“From December 4, the winds will slow down again. 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 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,” he said.

IMD also said that there is a forecast of shallow fog on December 4 or 5. The minimum temperature will go up and settle at 10-11 degrees Celsius in the next two days.

On Wednesday, the Safdarjung Observatory, which is considered the official reading for the city’s weather, recorded a minimum temperature of 8.2 degrees Celsius, a point below normal. The maximum settled at 26.7 degrees Celsius.