The national capital woke up to a dense fog on Wednesday with visibility falling to near zero at the Indira Gandhi International Airport around 8 am. The slight chill in the air and fall in temperatures signalled the arrival of winter, but the thick haze also raised fears of an impending smog episode.

It was not just the national capital, but many parts of Punjab, Delhi, west Rajasthan, and western Uttar Pradesh were also blanketed by a dense fog this morning, as visibility plummeted to zero in Amritsar, Suratgarh, as well as Bareilly. The latest forecast suggests the air quality is likely to remain in the “very poor" category over the next few days.
The Central Pollution Control Board (CPCB) recorded the daily Air Quality Index (AQI) in the capital to be around 334 on Tuesday, but it rapidly surged to around 387 by Wednesday afternoon, which falls in the “very poor" category. The levels of toxic PM10 and PM2.5 concentrations remain far higher than the safe limits prescribed by the World Health Organization (WHO).

“The temperatures are falling gradually across northwest India. We expect a dense fog during night and morning over the region during the next few days," said RK Jenamani, senior scientist at the India Meteorological Department. The mercury is now hovering around 30-33°C during the day, dropping to 14 -18°C during the night, though it is still at least 2-4℃ above normal across several places, with significant humidity levels.

A thick layer of smog – a mixture of smoke/pollutants and fog – blankets Delhi every winter. The air pollution levels usually surge in November, favoured by winter conditions, high vehicular emissions, and smoke intrusion from neighbouring states due to stubble burning. However, this time, the relatively warm weather conditions so far, combined with reduced fire counts, curtailed the daily average AQI to the “very poor" range.

Only 89 fire counts were recorded from Punjab and Haryana on Tuesday. According to the Indian Agricultural Research Institute (IARI), the stubble burning cases have fallen sharply in Punjab – from 24,717 in 2023 to 7,112 this year.

“At this time of the year, Delhi typically sees smog, and pollution levels are high. However, this year, the warm weather has provided some relief. We just had the warmest October in years, and temperatures are still above normal in Delhi. Additionally, stubble burning has been lower than last year – which helped reduce peak pollution levels. The winds are primarily blowing from the northwest at 8-15 mph," said Dr Gufran Beig, founder of, the System of Air Quality and Weather Forecasting and Research (SAFAR).

According to scientists, the AQI began to spike after 9 pm on Tuesday, when the weather conditions also began to take a turn. The Palam airport recorded the lowest visibility at zero metres at 8 am which improved to around 200 metres by 10 am. The visibility also dropped to its lowest in Safdarjung, to 200 metres by 7 am.