The Early Warning System for Delhi (EWS) reported that conditions are still unfavorable for pollutant dispersion, with no major improvement in air quality anticipated until Friday.
Delhi’s air quality stayed at the higher end of the “very poor” category for the fourth consecutive day on Wednesday, as calm winds continued to hinder pollutant dispersion, and a shallow fog covered the city for the second day.
The India Meteorological Department (IMD) reported that visibility dropped to around 800 meters at 7 a.m. and remained similar over the following hour. “Winds were calm, and shallow fog was observed for the second consecutive day. On Tuesday, during the season’s first instance of shallow fog, visibility also decreased to 800 meters,” an IMD official noted.
An average air quality index (AQI) of 356 (very poor) was recorded at 9 a.m., showing a slight improvement from Tuesday’s 4 p.m. reading of 373 (very poor).
The Early Warning System for Delhi (EWS) stated that conditions remain unfavorable for pollutant dispersion, with no significant changes expected in air quality. It forecasted that the air quality would likely remain in the “very poor” category until Friday.
Data from the Central Pollution Control Board (CPCB) revealed that at least four stations recorded air quality in the severe category at 9 a.m. on Wednesday. NSIT recorded an AQI of 444, while Wazirpur had an average AQI of 421.
The CPCB classifies AQI as follows: 0-50 is “good,” 51-100 is “satisfactory,” 101-200 is “moderate,” 201-300 is “poor,” 301-400 is “very poor,” and over 400 is “severe.”
According to CPCB data, Delhi’s AQI has reached the severe category at least once by November 6 every year since 2015. The earliest occurrence of severe AQI since 2015 was on October 20, 2017. Typically, this happens between the last week of October and the first week of November. It was recorded on November 1 in 2015, October 29 in 2016, October 30 in 2018 and 2019, November 5 in 2020 and 2021, November 1 in 2022, and November 3 last year.
Strong winds after Diwali and higher-than-normal temperatures were key factors in preventing the AQI from reaching the severe level this season.
Anumita Roychowdhury, Executive Director (Research and Advocacy) at the Centre for Science and Environment, explained that despite Diwali falling on October 31, the strong winds and elevated temperatures helped disperse pollutants quickly. “This year, the overall temperature has been higher throughout October, not just towards the end of the month. However, it’s important to note that the AQI was still in the very poor category even in October, indicating that background emissions are high. A further drop in temperature could push the AQI into the severe category.”
Delhi Environment Minister Gopal Rai announced on Tuesday the launch of a campaign to monitor and prevent open waste burning, starting Wednesday. He also stated that 588 teams would be deployed across the city for this effort.
Rai conducted a review meeting on air quality with 33 government departments on Tuesday. He mentioned that Resident Welfare Associations, government departments, and construction sites have been instructed to provide heaters to night-time workers and security guards to prevent them from using firewood for warmth.