According to airport officials, fog disrupted the schedules of over 50 domestic and international flights.
"Fog started enveloping the airport from 10 pm last night and runway visibility dropped to 50 metres," an airport official said.
21 domestic and international flights were diverted while 15 others were cancelled.
Some other flights to Chandigarh, Jaipur and Shimla were also cancelled.
Around 10 international flights arriving here were delayed. Similarly, those departing also got delayed.
According to the Met department, the dense fog is likely to dissipate after 11 am on Wednesday, Jan 27.