NEW DELHI: The India Meteorological Department officially declared the withdrawal of the southwest monsoon from Delhi on Friday, making it a delay of 13 days from the normal withdrawal date of September 25. Colder winds from the northwest are expected in the coming days, leading to a drop in night temperature but a deterioration in air quality. The overall AQI had already begun to touch the higher end of the ‘moderate’ category on Friday, with two stations in Delhi even recording ‘very poor’ air in the morning.
A delayed withdrawal hasn’t been uncommon since 2015. In 2019, the monsoon departed on October 10 and on October 8 in 2016. In fact, based on data for the past three decades, the normal date of monsoon withdrawal from Delhi was recently revised from September 21 to four days later.
During the monsoons this year, officially between June 1 and September 30, Delhi received 1,169.7mm of rainfall against the normal 648.9mm — an excess of 80%. To put this in perspective, the city received 404.3mm of rainfall in the 2019 season and 576.6mm last year. With the 3.4mm additional rainfall in October, 2021 had the third wettest season for Delhi, behind 1964 with 1,190.9mm of rainfall and 1933 with 1,420.3mm.
“The southwest monsoon has withdrawn from some more parts of Gujarat, most parts of Rajasthan, entire Punjab, Haryana, Chandigarh and Delhi, Jammu & Kashmir, Ladakh, Himachal Pradesh, Uttarakhand and some more parts of Uttar Pradesh and Madhya Pradesh today,” said IMD’s bulletin on Friday.
A met official explained that the withdrawal ushered in changes in meteorological conditions, including wind direction, with cooler winds expected to blow in from the northwest. While the days may be warm, night temperatures may drop 2-3 degrees Celsius in the next seven days.
Air quality will suffer now, with the overall 24-hour AQI on Friday spiking to 167 from 127 on Thursday. In the morning, the two stations at Dwarka and Anand Vihar had the air in the ‘very poor’ category with AQI of over 300. The Shadipur station logged an AQI of 206 (poor).
The system of Air Quality and Weather Forecasting and Research, a government forecasting body, predicted deterioration in air quality in the next three days owing to a mixture of colder air and stubble burning in northwest India.
“Delhi’s AQI is in the moderate category with PM10 as main pollutant due to fusion of cold, dry and polluted air with fire emissions and local road dust re-suspension,” said SAFAR. Delhi’s air would be between moderate and poor levels for the next three days, it added.
