Flight operations were largely unaffected at the IGI Airport on Thursday morning even as fog enveloped the area.
Though 12 flights were delayed, it was due to bad weather in the destination cities like Chandigarh, Kolkata, Amritsar and Lucknow.
Four flights, including an international one, were cancelled due to operational reasons, officials said.
Though there was fog at the airport, the visibility at the runway did not dip below the prescribed minima for low visibility take off of 125 metres and 150 metres for large and small aircraft.
The visibility did not dip beyond 200 metres after 6 AM, when the flights start to depart from here, an airport official said.
Yesterday, around 250 flights were affected after dense fog kept the airport under wraps, leading to visibility dipping to less than 50 metres.
Flights were unable to take off for more than five hours.