Dense Fog Triggers Red Alert In Delhi; 128 Flights Cancelled, AQI Slips To ‘Severe’
The India Meteorological Department warned that dense to very dense fog is expected to persist through the night and into the morning of December 30.

A thick blanket of dense fog and smog has gripped Delhi and large parts of north India, severely disrupting daily life, flight operations and road traffic. With visibility dropping sharply, authorities issued a red alert for fog in the national capital till Tuesday afternoon. At least 128 flights were cancelled as operations at Indira Gandhi International Airport were affected by CAT III conditions. The situation has been compounded by dangerously high air pollution levels, with Delhi’s Air Quality Index (AQI) crossing the 400 mark, placing it in the ‘Severe’ category.
Flights Cancelled, Traffic Hit Across Delhi
According to airport authorities, dense fog led to major disruptions in flight schedules, forcing airlines to cancel or delay operations. Passengers were advised to stay in touch with their respective airlines for real-time updates, while on-ground staff were deployed across terminals to assist travellers.
Passenger Advisory issued at 23:00 hrs.
— Delhi Airport (@DelhiAirport) December 29, 2025
Please click on this link for real-time winter travel updates: https://t.co/Y0B6lhwIj4#DelhiAirport #PassengerAdvisory #DELAdvisory pic.twitter.com/TnKXUsoMto
Road traffic was also hit as thick fog engulfed several parts of the city, including Saket and the ITO area. Visuals from key junctions showed low visibility conditions, making commuting difficult during early morning hours. Authorities urged motorists to drive cautiously, use fog lights and avoid unnecessary travel.
VIDEO | Dense fog engulfs Saket area in Delhi making commute difficult. The AQI has also went past 405.#Delhi #Fog pic.twitter.com/JL609VUDdL
— Press Trust of India (@PTI_News) December 29, 2025
#WATCH | Delhi: Visuals around the ITO area as a layer of smog engulfs the national capital.
— ANI (@ANI) December 29, 2025
AQI (Air Quality Index) around the area is 407, categorised as 'Severe', as claimed by CPCB (Central Pollution Control Board). pic.twitter.com/VY1Mgi1svN
Air Quality Slips To ‘Severe’ Category
The fog episode coincided with a sharp deterioration in air quality. Data from the Central Pollution Control Board showed AQI levels around 405 to 407 in several parts of Delhi, categorised as ‘Severe’. Poor dispersion conditions due to calm winds and low temperatures have worsened pollution levels, raising health concerns, particularly for children, the elderly and those with respiratory conditions.
IMD Issues Widespread Fog Alert
The India Meteorological Department warned that dense to very dense fog is expected to persist through the night and into the morning of December 30 across multiple regions. These include Delhi, Haryana, Punjab, Chandigarh, Uttar Pradesh, and parts of east, north and north-east India.
FOG ALERT !
— India Meteorological Department (@Indiametdept) December 29, 2025
Dense to very dense fog is expected tonight and into the morning of 30th December across several regions including Haryana, Chandigarh & Delhi, Punjab, Uttar Pradesh, and parts of the Northeast, East, and North India. Visibility may be severely reduced, making travel… pic.twitter.com/LvAA2yOboz
The weather office cautioned that visibility may be severely reduced, increasing the risk of accidents on roads, railways and at airports. It advised people to drive slowly, use appropriate lighting, and limit travel where possible.
With fog and pollution levels remaining high, authorities continue to monitor the situation closely, while residents brace for further disruptions until weather conditions improve.

























