The Centre said it was monitoring the situation at the Indira Gandhi International Airport where flight operations were affected this week because of heavy fog, PTI reported.
In addition to the fog, the air quality of Delhi has not really improved much, and is still at the "very poor" mark.
T1-D and T3 and the boarding gates were jam packed with passengers, many sitting on the floor and staircases and waiting for word about their delayed flights. Even train services had been hit by fog.
Meanwhile, despite the morning chill and dense fog, the Republic Day parade rehearsal took place. A total of 62 trains have been delayed. Delhi is reeling under the intense cold wave with current temperature in the national capital is 10°C.
At least 14 trains were cancelled, over 60 delayed and 18 trains has been rescheduled due to the thick fog in several parts of the northern India. "Due to dense fog the visibility came down to 50m at Safdarjung at 8.30am, while it was less than 50m at Palam", said an official at India Meteorological Department.
As cold wave continues to grip Delhi-NCR on Thursday morning, trains and flight schedule has adversely been affected by the low visibility.
Over 500 flights, both domestic and worldwide, flying into and out of the IGI Airport have been affected since Sunday, when the city witnessed the worst fog of the season.