Delhi’s air quality nears severe; IMD warns of cold wave from Tuesday

The Central Pollution Control Board (CPCB) bulletin showed that the overall air quality index of Delhi on Sunday was 396, in the ‘very poor’ zone.

Delhi’s air quality deteriorated on Sunday, reaching the end of the very poor category -- just four away from the severe zone even as the Met office predicted cold wave conditions in the city.

People gathered around a bonfire on a winter evening at Yamuna Pusta Road in New Delhi. (Raj K Raj/HT PHOTO)

India Meteorological Department (IMD) has forecast that the minimum temperature in Delhi may drop to 3 degrees Celsius from December 29. On Sunday, the minimum temperature at the Safdarjung observatory was 6 degrees Celsius, while the maximum temperature was 22.6 degrees Celsius.

The Central Pollution Control Board (CPCB) bulletin showed that the overall air quality index of Delhi on Sunday was 396, in the ‘very poor’ zone. However, by 8pm it deteriorated to 407. At least 25 out of the 36 pollution monitoring stations were in the severe zone, according to Sameer app of the CPCB.

On Saturday, the AQI was 337, also in the ‘very poor’ category. So far this month, the air quality in Delhi was severe for four days and moderate for just one day on December 14, CPCB data shows.

IMD scientists warned that the air quality could deteriorate further over Sunday night.

VK Soni, head of IMD’s environment monitoring research centre, said on Sunday Delhi received winds from the northeastern direction, which was high in moisture. This means that air quality will deteriorate over Sunday night and may enter the severe zone, he said.

“The high moisture in the air will keep the pollution levels high, but from Monday morning the wind direction will change back to northwesterly. The wind speed will also improve slightly, which will result in a marginal betterment of the AQI,” said Soni.

He, however, added that the improvement will not be significant and the AQI on Monday is also likely to remain in the very poor zone.

Union ministry of earth science’s System of Air Quality and Weather Forecasting and Research forecast also said that from Monday, Delhi’s air quality is expected to improve.

“The surface winds are likely to pick up and AQI is likely to improve to the middle-range of very poor for December 28 and December 29. AQI is likely to deteriorate thereafter towards the high end of very poor by December 30 and December 31,” the Safar analysis read.

According to IMD, under the influence of an approaching western disturbance, there was snowfall over Jammu and Kashmir, Ladakh, Gilgit, Baltistan and Muzaffarabad. Scattered snowfall over Himachal Pradesh, Uttarakhand and light rain and thundershowers were also noticed in the northern parts of Punjab, Haryana and Chandigarh. The impact of this will be seen on Delhi’s temperatures from December 29.

Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, said on Monday the minimum temperature will be around 5 degrees Celsius but this will dip and reach to around 3 degrees Celsius in the coming days.

“In Delhi, we can expect clouds and trace rainfall. After the WD passes, cold wave conditions are likely to stay for three to four days from December 29 onwards. We are already recording very low minimum temperatures bordering cold wave conditions,” said Srivastava.