Delhi’s air quality index (AQI) is likely to improve slightly on Thursday because of a change in wind direction, but will worsen over the weekend.
Central Pollution Control Board (CPCB) data showed that the AQI at 6 am on Thursday was 251, which fell in the poor category.
AQI between 201 and 300 is considered in the poor category.
Delhi’s average AQI was 256 on Wednesday.
Scientists at the India Meteorological Department (IMD) had forecast that the wind direction would change to north-easterly on Thursday, which could lessen the impact from stubble burning in the neighbouring states of Punjab, Haryana and western Uttar Pradesh (UP).
However, they warned that the AQI would worsen on Friday and Saturday (October 23-24) due to reduced wind speed.
“We are expecting that the AQI will worsen because of a reduction in the wind speed from Friday. The AQI may touch the lower end of the very poor category,” said a senior scientist.
The average wind speed is likely to remain up to 10 kilometres per hour (kmph) and may even reduce further over the next three-four days.
Slow wind speed and a drop in temperature are not favourable for dispersion of pollutants, they added.
The national capital’s minimum temperature on Wednesday had dipped to 14.3 degrees Celsius (C), four notches below normal.
The maximum temperature was 35.2 degrees C, two notches above normal.
The minimum and maximum temperatures would be around 14 and 35 degrees C, respectively, over the next three-four days, the scientists said.
As per the System of Air Quality and Weather Forecasting and Research (SAFAR), and the Union Ministry of Earth Sciences’ (MoES) air quality forecasting wing, the AQI would worsen in the national capital over the weekend.
