Delhi AQI in ‘severe’ category on Friday, unlikely to improve over weekend
Delhi’s air quality on Friday morning touched the ‘severe’ category after being in the ‘very poor’ category for six consecutive days until Thursday.
Delhi’s air quality index (AQI) at 7.05am on Friday stood at 401 (severe).
This is a deviation from the forecasts on Thursday, which had indicated that Delhi’s AQI was expected to remain ‘very poor’ on Friday, and possibly touching severe only on Saturday.
“Delhi’s air quality is likely to remain in the ‘very poor’ category on Friday. The air quality is likely to be in the ‘severe’ category on Saturday and back in ‘very poor’ again on Sunday,” the Early Warning System (EWS) for Delhi, a forecasting model used by the (CAQM) in NCR, had sCommission for Air Quality Management aid on Thursday.
An AQI of 51 to 100 is classified as ‘satisfactory’, between 101 and 200 is classified as ‘moderate’, between 201 and 300 is classified as ‘poor’, between 301 and 400 is classified as ‘very poor’ and over 400 is ‘severe’ by the Central Pollution Control Board (CPCB).
On Thursday, the AQI had marginally improved in comparison to Wednesday as dipping temperature and calm winds at night provided no respite to the capital. Delhi’s 24-hour average air quality index (AQI) was recorded at 390 (very poor) as per Central Pollution Control Board’s national bulletin at 4 pm on Thursday, with it recorded at 395 (very poor) at the same time on Wednesday.
Though Delhi has recorded eight ‘severe’ air days so far this month – when the AQI has been over 400, it has been on the brink of severe – 390 or higher on another six days, making it 14 such days with an AQI of 390 or higher. This is the highest tally of such days in November in the last eight years, with the previous high of 13 such days coming in November 2021.
Last year, Delhi recorded three such days, nine in 2020, eight each in 2019 and 2018, seven in 2017, 11 in 2016 and seven in 2015.
The wind direction on Friday morning was southeasterly. The India Meteorological Department (IMD) has said there is likely to be a change in wind direction on Friday, with it largely remaining easterly, until a western disturbance brings light rain over Delhi on November 27.
Delhi’s minimum temperature is also expected to remain low, hovering around 10-11 degrees Celsus from Friday until the weekend, rising to 13 degrees by November 27. Delhi’s minimum on Thursday was 9.2 degrees Celsius – two degrees below normal and the lowest so far this season.
Low temperatures make the atmosphere more stable, aiding calm wind conditions and making the dispersal of pollutants difficult.
Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE) said even though Delhi got some respite before Diwali due to rain, pollution levels have shot up once again post the festival, giving Delhiites a long spell of fairly high exposure.
“On paper, the AQI may be very poor, but a difference of a few points between 390 and 400 will not make much difference and this exposure is still fairly high. It is worrying from a health point of view and highlights the need for requiring much stronger action not just in Delhi, but across NCR too,” she said.