Delhi’s air quality is forecast to deteriorate from the moderate category to poor levels on October 21 and 22, even as the city recorded its lowest minimum temperature of the month so far at 17.1 degrees Celsius on Monday morning.
The minimum temperature at the Safdarjung weather station, Delhi’s base station, was 1.3 degrees Celsius below the seasonal average, according to the India Meteorological Department. The maximum temperature during the day was 31.7 degrees Celsius.
The Central Pollution Control Board recorded Delhi’s 24-hour average Air Quality Index at 139 at 4 pm on Monday, placing it in the moderate category. Of the 58 monitoring stations that reported data, two recorded poor air quality, six were in the satisfactory category and the rest reported moderate levels.
Pusa recorded the highest AQI among the monitoring locations at 281, which falls in the poor category. Under the CPCB classification, an AQI of 101 to 200 is considered moderate, while readings between 201 and 300 are classified as poor.
The Air Quality Early Warning System forecast that Delhi’s air quality would remain moderate on October 19 and 20 before worsening to poor on October 21 and 22. Its outlook for the following six days also indicated poor air quality. The system attributed the expected deterioration to unfavourable meteorological conditions that could restrict the dispersal of pollutants.
A ventilation index below 6,000 square metres per second, combined with average wind speeds below 10 kmph, is considered unfavourable for pollutant dispersion. These conditions can allow emissions to remain concentrated near the surface, affecting air quality across the city even when pollution levels vary between monitoring stations.
The air-quality forecast comes as satellite data recorded 98 stubble-burning events across six states on October 19, according to the Consortium for Research on Agroecosystem Monitoring and Modelling from Space laboratory at the Indian Agricultural Research Institute. Uttar Pradesh accounted for 27 events, followed by Punjab with 25, Rajasthan with 24, Uttarakhand with 18 and Madhya Pradesh with four.
The distribution of monitoring results shows that Delhi’s air quality was not uniform across the city on Monday. While the citywide average remained moderate, Pusa had already entered the poor category, illustrating how local conditions and emissions can produce significantly different exposure levels within the same urban area.
The immediate official outlook is for moderate air quality through October 20, followed by a forecast shift to poor conditions from October 21. The Air Quality Early Warning System’s six-day outlook will continue to guide monitoring of the expected deterioration.
