Delhi, which has been battling smog and poor air quality since the beginning of winter, ranked third among the world's most polluted capitals in Friday's live rankings by Swiss group IQAir.
No diversion or cancellation has been reported yet, an airport spokesperson said, although authorities warned in a post on X that aircraft lacking equipment to enable landings in low visibility could face difficulties.
On social media, India's largest airline IndiGo and low-cost carrier Spicejet also cautioned against weather delays.
Delays averaged eight minutes for 20 flights by 10:14 a.m., aviation website FlightRadar24 said.
Some train services in the capital were also delayed, media said.
New Delhi's air quality was rated "very poor" on Friday, with an index score of 351, the country's top pollution control body said, well beyond the levels from zero to 50 that it considers "good".
