Dense fog enveloped the Indira Gandhi International Airport in New Delhi on Monday morning, disrupting the schedule of around 40 flights.
Overnight around 16 flights were delayed.
Around five flights were cancelled either due to operational reasons or due to poor weather, an airport official said.
Fog started to descend on the airport from last night but it started to become dense around 7am, forcing authorities to implement low visibility procedures.
Dense fog returned to the capital on Sunday after a four-day lull, affecting over 130 flights.