Delhi breathes ‘very poor’ air; dense fog, light rain likely over next two days

New Delhi: Dense fog is expected to continue over Delhi on Wednesday, with generally cloudy skies and light rain likely on New Year’s Day, even as air quality remains under stress and transport services face ongoing disruption, according to the India Meteorological Department.

On Tuesday, the national capital’s air quality showed marginal improvement but stayed in the very poor category. Data from the Central Pollution Control Board indicated that the 24-hour average Air Quality Index stood at 388, compared with 401 a day earlier. Pollution levels were uneven across the city, with 17 monitoring stations recording very poor air and another 17 registering readings in the severe range. Anand Vihar reported the worst conditions with an AQI of 460, according to CPCB’s Sameer app. Under the official scale, AQI values between 301 and 400 are classified as very poor, while 401 to 500 are considered severe.

The Air Quality Early Warning System projected that the AQI is likely to slip back into the severe category on December 31 and January 1, before easing to very poor on January 2. For the following six days, air quality is expected to remain very poor. Officials attributed the outlook to unfavourable meteorological conditions, citing a ventilation index below 6,000 square metres per second and average wind speeds of less than 10 kilometres per hour, which limit the dispersion of pollutants.

An assessment by the Decision Support System for Air Quality Management showed that Delhi transport was the largest contributor to pollution on Tuesday at 15.3 per cent. Industries in the city and its peripheral areas accounted for 7.6 per cent, followed by residential sources at 3.7 per cent, construction activities at 2 per cent and waste burning at 1.3 per cent. Among NCR districts, Jhajjar emerged as the biggest contributor at 18.2 per cent, followed by Rohtak at 4.7 per cent, Bhiwani at 4.4 per cent, Gurugram at 1.8 per cent and Sonipat at 1.4 per cent.

Weather conditions added to the challenges during the morning hours. Visibility dropped sharply due to dense fog, measuring around 100 metres at Safdarjung at 7.30 am before improving to about 200 metres by 8.30 am. At Palam, moderate fog prevailed with visibility near 300 metres at 8.30 am. Delhi recorded a maximum temperature of 21.5 degrees Celsius, which was 1.1 degrees above normal, and a minimum of 9.4 degrees Celsius, 2.6 degrees above normal. For Wednesday, the IMD forecast a minimum temperature of around 8 degrees Celsius and a maximum of about 23 degrees Celsius. The fog severely disrupted flight operations at the Indira Gandhi International Airport, which handles about 1,300 flights daily. At least 118 flights were cancelled, including 60 arrivals and 58 departures, while 16 flights were diverted. Flight tracking data showed around 130 delayed services on Tuesday morning, with average departure delays of roughly 28 minutes. In a post on X, Delhi International Airport Ltd said flight operations were continuing, noting that services not compliant with CAT III norms could be affected in low visibility conditions. Against the backdrop of fog and delays, the civil aviation ministry directed airlines to strictly adhere to passenger facilitation norms. These include providing timely flight information, meals for delayed passengers, rebooking or refunds in case of cancellations, ensuring no denial of boarding after timely check-in, baggage assistance and prompt grievance redressal.