As the cold wave tightened its grip on northern India, the air quality dipped to the 'severe' category on the last day of the year, according to the Central Pollution Control Board data on Sunday.
According to the IMD, a Yellow Warning has been issued of 'Dense Fog' very likely to occur at one or two places over the districts of Koraput, Malkangiri, Nawarangpur, Kalahandi, Sonepur, Bolangir, Sambalpur, Jharsuguda, Bargarh, Sundargarh, Deogarh and Ganjam.
The winter chill continues to grip North India, as cities such as Prayagraj in Uttar Pradesh, Jaipur in Rajasthan and Sambalpur in Odisha faced cold waves, engulfed in dense fog on Saturday morning.
Fog is categorised as "very dense" when the visibility goes below 50 metres. On the other hand, if the visibility is between 51 to 200 metres, it is considered "dense" fog and "moderate" fog prevails when the visibility is between 201 and 500 meters.
Due to the thick fog, several flights in the Delhi Airport were delayed. The low visibility also delayed arrival and departure of several Delh-bound trains.
An INSAT (Indian National Satellite System) imagery released by the Met department on Thursday depicted fog hovering over the North India region.
The satellite image taken at 1430 hrs (IST), showed a fog layer continuing over Punjab, Haryana, extreme north Rajasthan, Uttar Pradesh, and north
UPSRTC officials said that buses should not operate in case of poor visibility due to fog. The corporation also advised operators to park buses at safe locations and wait until visibility improves.
The Delhi airport reported delays in flight operations affecting approximately 134 flights, both arrivals and departures (domestic and international), due to fog. As many as 22 trains were delayed at the New Delhi Railway Station as well, amid low visibility.
Air India has announced today that passengers travelling to and from Delhi IGI airport during the winter season can reschedule or cancel their bookings at no additional cost if major fog delays are anticipated.