New Delhi: Delhi witnessed its first spell of dense winter fog on Monday, with visibility dropping to zero in parts of the city and bringing air, rail and road transport to a standstill. Flight operations at Indira Gandhi International (IGI) Airport were severely disrupted, with departures suspended for nearly five hours between 4am and 9am, when visibility fell below 100 metres.
Officials said 228 flights — including 131 departures and 97 arrivals — were cancelled, more than 800 were delayed and five were diverted to other airports. The disruption continued well after the fog began to lift around noon, while at least 100 trains were also reported to be running late.
According to the India Meteorological Department (IMD), visibility started deteriorating sharply on Sunday night. It fell to 150 metres by 11.30pm and dropped to zero at Safdarjung, the city’s base station, by 12.30am on Monday. Zero visibility persisted until 2am, improving marginally to 100 metres by 2.30am. At Palam, the lowest visibility recorded was 50 metres at 4am.
Conditions began improving after 9am, with visibility at Safdarjung rising to 300 metres by 9.30am and 700 metres by 10.30am as sunlight broke through. At Palam, visibility improved from 100 metres at 9am to 300 metres by 10.30am and reached 500 metres by noon.
Flight operations at IGI were hit hardest from 4am, when visibility dipped to 50 metres and low-visibility procedures were activated. Data from flight-tracking website Flightradar24 showed that by Monday evening, around 260 arriving flights and 400 departing flights had been delayed. Airport officials said delays were compounded as aircraft arriving late from other fog-affected airports were unable to depart on schedule.
Officials explained that pilots trained in CAT III operations can land aircraft in visibility as low as 50 metres, while take-offs require a minimum of 125 metres. However, pilots not certified for CAT III need visibility of around 500 metres to take off, forcing aircraft to wait on taxiways even after boarding is complete and leading to cascading delays.
The disruption was not limited to Delhi. Several airports across north India were affected by dense fog. The civil aviation ministry said on X that some flights could be delayed, diverted or cancelled, advising passengers to stay in touch with airlines for real-time updates and to plan for additional travel time.
IndiGo said low visibility due to dense fog had severely impacted operations at Delhi and other northern airports, calling the situation beyond the airline’s control. “While operations adjust to prevailing weather, some flights may be delayed and a few may be proactively cancelled to prioritise safety and minimise extended waiting at airports,” the airline said.
Air India also said poor visibility had affected all airlines’ operations, adding that some flights were cancelled in the interest of safety and to avoid prolonged uncertainty for passengers.
The civil aviation ministry said the Director General of Civil Aviation had reviewed preparedness for fog conditions and directed officials to closely monitor passenger inconvenience and ensure airlines adhere to standard operating procedures and issued guidelines.
