Delhi recorded its lowest minimum temperature of the month so far on Monday, while the city’s air quality is forecast to deteriorate from the moderate category to poor levels from October 21, raising the likelihood of worsening pollution conditions across the capital.
The minimum temperature at the Safdarjung weather station, Delhi’s base station, settled at 17.1 degrees Celsius, 1.3 degrees below the seasonal average, the India Meteorological Department said. The maximum temperature for the day was recorded at 31.7 degrees Celsius.
An IMD official said the reading marked the coldest night temperature recorded in the city so far this month. The fall in temperature comes as air pollution levels remain moderate but are expected to worsen over the next few days.
According to the Central Pollution Control Board, Delhi’s 24-hour average Air Quality Index stood 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 remaining stations reported moderate levels.
Pusa recorded the worst air quality among the stations, with an AQI of 281, which falls in the poor category. Under CPCB classifications, an AQI of zero to 50 is considered good, 51 to 100 satisfactory, 101 to 200 moderate, 201 to 300 poor, 301 to 400 very poor and 401 to 500 severe.
The Air Quality Early Warning System has forecast that Delhi’s air quality will remain moderate on October 19 and 20 before deteriorating to poor levels on October 21 and 22. Its outlook for the following six days also indicates poor air quality.
The system said unfavourable meteorological conditions could hamper the dispersal of pollutants. A ventilation index below 6,000 square metres per second, combined with average wind speeds of less than 10 kmph, is considered unfavourable for pollutant dispersion. Such conditions can allow emissions to remain concentrated near the surface instead of being carried away.
Satellite data also 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 ICAR-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 latest forecast places Delhi at a critical seasonal transition, with temperatures beginning to fall and atmospheric conditions expected to become less favourable for pollutant dispersal. The Air Quality Early Warning System’s forecast for October 21 and 22 remains the next key assessment for the city’s pollution levels.
