The dense fog reduced visibility to as low as 10 m at around 0530 hours which disrupted flight schedules at the International airport.
The cold Northwesterly winds maintained severe chill in the Delhi air with the maximum temperature plummetting to 14 degrees Celsius, which was nearly seven degrees below normal.
Arrival of about 40 flights, including 23 International flights, was delayed by four to five hours, a spokesperson of the Airports Authority of India said.
Various methods to retain visibility had to be put in force, the spokesperson said. However, visibility levels improved to 100 metres by 1100 hours.
The fog led to cancellation of many flights while departure of nearly 30 flights, including seven International flights, was delayed.
Weathermen attribute the dense fog in the Capital to the ground frost conditions prevailing over isolated pockets of Punjab, North Haryana and North Rajasthan.
The ground frost in Northwest India also led to continuance of the severe chill sweeping Delhi in the last few days, even though the minimum temperature rose to 8.7 degrees Celsius.
Weathermen have forecast that the cold wave conditions and foggy weather were likely to prevail in Delhi during the next two days.
For the next 24 hours, they have forecast a cold and foggy day in Delhi. They have also forecast a drop in minimum temperature to 8 degrees C.