The minimum temperature was recorded at 5.7 degrees Celsius, a notch below the season's average.
All the terminals at the Indira Gandhi International (IGI) Airport were packed with passengers, who drove on fog-covered roads to catch their morning flights.
Due to Dense fog in Delhi fifty-six trains in the national capital were delayed, 20 rescheduled and 15 cancelled as the visibility the region dropped sharply.
While planes could land in Delhi, they were delayed because of unavailability of parking bays, which were occupied by aircraft waiting to take-off, the official said.
Dense fog engulfed the Delhi airport in the morning hours, resulting in dropping of visibility below 50 m. A large number of flights and trains were delayed.
At railway stations across north India, hundreds of passengers were also left stranded after multiple trains got delayed due to the thick fog today. With 23 flights cancelled, all of which were domestic ones, according to airport an official.No take-offs could take place between 7:30 am and 9:30 am, according to an airport official. The visibility later improved to 100 metres at 3 a.m. and to 200 metres at 6 a.m. The maximum was likely to hover around 21 degrees. The humidity at 8.30 a.m. was 97% and the visibility was 300 metres.
Departures require a visibility of at least 125 metres, while planes can land in visibility below 50 metres if the pilots are trained in CAT IIIB technology for low-visibility landings that allows qualified aircraft to land in visibility of 25-50 metres.