The delay affected flight schedules across the country, especially those to/from Mumbai.
A Times of India report says that 28 arrivals to Mumbai and 22 departures were delayed by over an hour. A total of five departures and four arrivals to/from Delhi were cancelled.
Sources say that the fog became denser around 5 am and the visibility went below 50 metres. The minimum required for landing under poor visibility conditions using the CAT-III B instrument landing system (ILS) is 50 metres.
Delhi has been witnessing extreme weather for last few days. This was the first fog-induced delay of the season. However, this occurs every year since Delhi experiences harsh winter, say officials.
(With agency inputs)