Delhi, Dec 30, 2025: Flight operations at Indira Gandhi International Airport (IGI) were affected on Monday night as dense fog enveloped the national capital for the second consecutive day. The India Meteorological Department (IMD)issued alerts warning of dense to very dense fog in the coming hours.

Flight Operations and Advisories

Delhi airport operator DIAL issued a statement around 11 pm, confirming that operations were under CAT III conditions, which may lead to flight disruptions. Passengers were advised to:

• Verify flight status with airlines
• Expect possible delays or cancellations
• Allow extra travel time to the airport

Airlines such as IndiGo and Air India also issued advisories, warning of poor visibility affecting Delhi, Amritsar, Chandigarh, Jammu, Kolkata, Ranchi, Guwahati, and Hindon airports, with potential cascading effects across networks.

What is CAT III?

In aviation, CAT III (Category III) refers to an Instrument Landing System (ILS) approach that allows aircraft to land safely in extremely low visibility conditions caused by fog, rain, or snow.

• Decision Height (DH): CAT III allows landings with no decision height or a DH lower than 100 ft (30 m)
• Runway Visual Range (RVR): Minimum visibility can be as low as 700 ft (200 m)
• Purpose: Ensures a high level of safety during the most challenging weather conditions, enabling aircraft to land when visibility is insufficient for standard operations.
• Requirements:
  • Real-time visibility updates
  • Coordination between air traffic control and pilots
  • Advanced navigation and landing aids to guide aircraft safely

Impact on Passengers

• Early-morning flights may face delays or cancellations.
• Fog may affect takeoffs, landings, and runway operations, especially in northern India.
• Airlines are maintaining continuous monitoring and providing passenger support at terminals.

In short, CAT III operations allow planes to land safely even in near-zero visibility, but flight schedules can still experience disruptions due to dense fog, as seen at Delhi’s IGI airport.