Smog grounds over 350 flights in northern India

Dense fog and smog crippled flight operations at Delhi’s Indira Gandhi International Airport and across large parts of northern India on Monday, causing unprecedented delays and cancellations and leaving thousands of passengers stranded for hours.

In one of the worst fog disruptions this winter, aircraft movement at the capital’s airport slowed to a near halt, with just four flights managing to take off between 3:30 am and 9 am as visibility plunged to dangerously low levels.

Over 350 flights were cancelled and around 400 delayed across northern India as airlines struggled to cope with the rapidly deteriorating weather. Operations at Delhi airport were conducted under CAT III conditions, but even the highest low-visibility procedures failed to prevent large-scale disruption as fog reduced runway visibility below operational minimums for several aircraft and crews.

Due to low visibility, 228 flights (131-departure & 97-arrival) have been cancelled and five have been diverted so far, sources at the Delhi airport . The situation on the ground was described as “severely constrained”, with aircraft unable to depart, arrive or even vacate parking bays for long stretches of time.

As per sources, between 3.30 am and 9 am, only four flights could take off from Indira Gandhi International Airport. Around 3.30 am, seven aircraft were given start-up clearance but were not permitted to take off as visibility suddenly dropped. As a result, passengers were stuck inside aircraft for up to 10 hours, with some of these flights eventually being cancelled. The disruption worsened around 5:30 am, when all arrivals at the Delhi airport were suspended for nearly 90 minutes after parking bays became completely full. By 9 am, as many as 127 flights with passengers on board were stuck at parking bays, waiting for clearance to depart.

IndiGo faced widespread disruption, with dense fog and low visibility forcing delays and over 170 cancellations at Delhi and other airports across north India. The airline said flight movements were affected due to visibility dropping below operational limits.

Air India cancelled over 100 flights to and from Delhi due to the fog. The airline said poor visibility in Delhi had disrupted operations across carriers and that safety considerations had guided its decisions. “Poor visibility due to dense fog in Delhi this morning has impacted flight operations for all airlines. We are closely monitoring conditions and will resume operations as soon as it is safe to do so. In the interest of safety, and to avoid prolonged uncertainty for our guests, some flights have been cancelled,” Air India said.

Air India Express cancelled over 10 flights, while several SpiceJet and Akasa Air services were diverted or delayed at the Delhi airport as visibility conditions fluctuated during the morning hours.

The Ministry of Civil Aviation also issued a heavy fog alert for northern India, advising passengers to check flight status before travelling and allow extra time for road movement, which was also slowed by poor visibility. Senior officials of the ministry visited the Airport Operations Control Centre at Delhi airport to review real-time operations amid growing passenger distress.

“In view of the prevailing fog conditions at Delhi Airport, senior officials of the Ministry of Civil Aviation visited the Airport Operations Control Centre and reviewed real-time operations. Airports have been instructed to maintain close coordination with stakeholders, ensure timely dissemination of information, and facilitate passenger convenience. Passenger safety and smooth operations remain our top priority,” the ministry said.

The impact extended beyond Delhi, prompting the Chhatrapati Shivaji Maharaj International Airport in Mumbai to issue a travel advisory warning passengers of possible delays and cancellations due to disruptions in northern India. The ministry acknowledged that dense fog was severely affecting visibility at Delhi and other northern airports, with air traffic control and ground teams working to minimise disruption.

Fog remains one of the biggest winter challenges for aviation in north India. Even when airports operate under CAT III procedures, movement slows sharply. CAT III is the highest category of the Instrument Landing System, allowing landings in extremely poor visibility, but not all aircraft, pilots and runways are certified to use it simultaneously. Delhi airport’s CAT IIIB system permits landings in visibility as low as 50 metres, yet the combination of fog, congestion and certification limits continues to trigger severe disruption, turning winter mornings into long waits on the ground for thousands of passengers.