Delhi’s air quality is forecast to deteriorate to the severe category from Friday, with 18 of the national capital’s 59 active monitoring stations already recording severe pollution on Thursday, according to Central Pollution Control Board data. The worsening conditions come days before Diwali, when firecracker emissions can add to the city’s existing pollution load.
Delhi’s 24-hour average Air Quality Index stood at 369 at 4pm on Thursday, remaining in the very poor category for the fourth consecutive day. The reading was marginally lower than Wednesday’s 377, but higher than the average AQI of 350 recorded on Tuesday and 324 on Monday.
Jahangirpuri recorded the highest AQI among the monitoring locations, at 454 at 4pm. Under CPCB’s classification, an AQI between 301 and 400 is considered very poor, while readings from 401 to 500 fall in the severe category. The station-level data indicates that hazardous conditions are already concentrated in parts of the city even as the overall average remains below the severe threshold.
The Air Quality Early Warning System has forecast very poor air quality for Thursday, followed by a likely shift to the severe category from Friday through Sunday. Its outlook for the following six days places Delhi’s air quality in the severe to very poor range. The forecast makes weather and atmospheric conditions a key factor in how pollution levels will evolve across the capital.
Data from the Decision Support System for Air Quality Management in Delhi indicates that the contribution of stubble burning to the city’s pollution is expected to change over the coming days. The system estimated that stubble burning accounted for 15.601% of Delhi’s pollution on Thursday. Its projected share was 19.201% for Friday before falling sharply to 1.575% on Saturday.
The DSS projections for stubble burning’s contribution to PM2.5 are based on climatological data on fire counts and emissions rather than real-time farm-fire activity. At the same time, the projected contribution of transport emissions is expected to rise from 17.913% on Thursday to 18.291% on Friday and 21.108% on Saturday.
Sunil Dahiya, founder and lead analyst at Enviro Catalysts, said the expected fall in stubble burning’s share was primarily linked to changing weather conditions and did not necessarily indicate a decline in farm fires. He said Punjab had reported 2,347 farm fires during the season, including more than 700 on November 3 and 4.
Dahiya said a lower share of stubble burning would not automatically result in cleaner air because slower winds and morning mist could trap pollution from vehicles, industries, waste burning and firecrackers. He added that the early warning system had forecast severe air quality for November 6 and 7, while pollution from farm fires could return if north-westerly winds resumed.
The AQEWS bulletin said a western disturbance was expected to weaken the north-westerly winds that carry smoke from Punjab and Haryana towards Delhi and turn them easterly around Diwali. The immediate air-quality outlook will therefore depend on the interaction between regional smoke transport, local emissions and the city’s atmospheric conditions.
