At least 170 flights were cancelled at different airports and trains ran hours behind schedule as dense fog blanketed Delhi on Monday, reducing visibility to near zero and slowing early-morning traffic across the city.

According to souces, over 170 flights have been cancelled at various airports across the northern region including Amritsar, Varanasi and Noida. They also added that hundreds of flights wil be running delayed throughout the day due to the cascading impact.

The national capital on Monday morning remained enveloped in a thick layer of smog, with the city’s average Air Quality Index (AQI) settling at 498, firmly within the higher end of the ‘severe’ category.

Out of 40 air quality monitoring stations across the capital, 38 reported ‘severe’ air quality, while two stations recorded ‘very poor’ levels. Jahangirpuri emerged as the most polluted area, registering an AQI of 498, the highest among all stations.

As per the Central Pollution Control Board (CPCB), an AQI reading between 401 and 500 is classified as ‘severe’, posing serious health risks.

On Sunday, Delhi’s AQI had already surged to 461, marking the city’s most polluted day of the winter season and the second-worst air quality recorded in December so far.

Pollution levels were further aggravated by unfavourable meteorological conditions.