Arrival of about 40 flights, including 23 International flights, were delayed by four to five hours as the visibility dipped to 10 metres at around 0530 hours this morning, 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.
Consequently, traffic jams were also witnessed in several areas of Delhi.
The dense fog this morning came after the visibility levels remained at near normal levels for most of the days last week.
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 forecast said foggy weather would prevail for the next 24 hours.