India / Delhi will see colder days, cleaner air ahead: IMD

New Delhi: In the coming weeks, Delhi will get colder and continue to breathe cleaner air, according to the forecast by the India Meteorological Department (IMD).

IMD scientists said that the minimum temperature in Delhi may fall to 9 degrees Celsius by November 22, and there may be no drastic changes in the air quality. Delhi’s AQI has fluctuated between poor to severe and moderate in a matter of five days between November 13 and 17. From an AQI of 435 on November 15, which is in the severe zone, the air improved to poor (221) on November 16 and moderate (171) on Tuesday.

Sagnik Dey, associate professor at IIT Delhi, said the reduction in air pollution has been made possible partly because farm fires have reduced to almost zero and mostly because of the favourable meteorological factors such as good wind speed and light rain on Monday.

VK Soni, of IMD’s environment monitoring research centre, said that the average wind speed on Tuesday was around 15kmph, which helped disperse the pollutants in the air. “Our forecast is that even tomorrow (Wednesday) the air quality will remain in the moderate range. Even though the wind direction changed to north-westerly on Tuesday, because the stubble burning activity is almost over, its impact on Delhi’s air quality was almost negligible on Monday and on Tuesday,” he said.

Wind speeds are expected to remain high throughout the week, which will help keep the air quality in the range of moderate to poor, IMD scientists said.

Delhi on Tuesday recorded a minimum temperature of 13 degrees Celsius at the Safdarjung observatory, which is the official data for the city. The maximum temperature was 26 degrees Celsius, two degrees below the season’s normal. On Monday, the minimum temperature at the Safdarjung observatory was 16 degrees Celsius.

At the Palam observatory, the minimum temperature was recorded at 14.2 degrees Celsius, while the maximum temperature was 24.6 degrees C—nearly 3 degrees below normal.

Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, said that widespread snowfall in Jammu and Kashmir, Himachal Pradesh, upper reaches of Uttarakhand will lead to a fall in the minimum temperature by around 2 to 4 degrees Celsius over northwest India in the coming days.

“The winds have shifted to north-westerly from today (Tuesday) so cold winds will be blowing from the western Himalayas, where snowfall has just happened. We are expecting minimum temperature to drop to around 10 degrees Celsius in the next couple of days,” Srivastava said.

IMD data shows that till November 16, the average minimum temperatures recorded in the city have been around 2-3 degrees below what is considered normal for the season.. Data shows that last year the lowest minimum temperature recorded in the month of November was 11.4 degrees on November 20. On November 24, 2017, the lowest minimum temperature was recorded at 7.6 degrees.

Srivastava explained that since September Delhi had not received any impact of western disturbance, which kept the skies clear. Under such weather conditions, the ground cools faster and the minimum temperatures stay low.