Northern India has faced thick morning fog for several days. The conditions continued on Sunday and reduced visibility across many areas. The fog affected daily travel and slowed down air and rail movement.
At Delhi’s airport, more than 200 flights were delayed by Sunday morning, HT reported. Rail services also suffered. Northern Railways delayed over 50 trains due to poor visibility and bad weather.
Airports Authority of India issues warning
The Airports Authority of India warned passengers about possible disruptions. It said fog in several parts of northern India was affecting visibility at airports.
"Fog conditions in parts of Northern India are affecting visibility and may lead to delays or changes in flight operations at select airports. Passengers are advised to check flight updates with their airlines through official channels and allow extra time for airport travel and formalities," the advisory said.
Delhi airport says operations normal
Delhi airport issued its own passenger advisory at 10 AM on Sunday. It said flight operations at Indira Gandhi International Airport were continuing as usual.
However, the airport asked travellers to stay alert and confirm their flight status. "Operations at Delhi airport continue to be normal. For updated flight schedules, please consult your airline or visit the official airport website. We wish all passengers a safe and pleasant journey," the advisory posted on X said.
Passenger Advisory issued at 10:00 hours.
— Delhi Airport (@DelhiAirport) December 21, 2025
Please click on this link for real-time winter-ready travel updates: https://t.co/Y0B6lhwIj4#DelhiAirport #PassengerAdvisory #DELAdvisory pic.twitter.com/6au37stsNE
Smog worsens air quality in Delhi
Along with fog, Delhi also woke up to heavy smog on Sunday morning. A thick layer of pollution reduced visibility and caused discomfort across the city.
The Central Pollution Control Board recorded Delhi’s overall Air Quality Index at 390 around 7 AM. This placed the air quality in the 'very poor' category.
Several parts of the city saw even worse conditions. Pollution levels in many areas reached the 'severe' category. Dense haze continued to hang over the capital as air quality remained dangerously high.