In light of worsening weather conditions in the northern region of the country, the India Meteorological Department (IMD) issued a red alert for dense fog in Delhi, Punjab, Haryana, Chandigarh, Uttar Pradesh, Rajasthan, and Jammu and Kashmir, with winter chill. Delhi and NCR recorded 17 straight hours of dense fog between 7 pm on Thursday and 11.30 am on Friday, marking the longest dense fog spell of the season.
Issuing a “cold day” alert, IMD said “dense to very dense fog” is likely to be witnessed in Delhi and NCR for the next two days. “Cold day conditions are very likely in some to many parts of Delhi on December 30 and 31,” the IMD reported.
INSAT imagery released by the Met department showed that nearly 30 per cent of India’s population is experiencing visibility under 50 metres due to a dense fog layer over north India, affecting regions in Punjab, Haryana, Rajasthan, Uttar Pradesh, and northwest Madhya Pradesh. Experts have advised people not to venture out in their vehicles between 4 am and 10 am unless it is unavoidable.
In an advisory on Friday, the IMD urged people to use fog lights while driving and to stay in touch with airlines, railways, and state transport for schedule updates, as dense fog may affect rail, air, and highway routes. The impact of dense fog was evident through low visibility conditions leading to traffic disruptions and accidents. Several trains and flights have been delayed due to obstructed visibility, with the IMD recording the lowest visibility of 50 m at Palam in Delhi between 5.30 am and 7.30 am on Friday, improving to 150m by 8 am.
Despite low visibility, no flight diversions or cancellations were reported at Delhi’s Indira Gandhi International airport, though over 100 international and domestic flights faced delays, owing to low visibility. Airports classify a flight as “delayed” when it is late by more than 15 minutes. The Runway Visual Range (RVR) is currently within the range of 400 metres to 800 metres, according to the India Meteorological Department.
Amid dense fog disrupting flight operations at the Delhi airport in the last few days, Civil Aviation Minister Jyotiraditya Scindia said the Ministry is coordinating with the airport and airlines, and putting in place measures to deal with the issue. Terming the fog issue as a “transitory phenomenon,” the minister also said this year the situation has been slightly unprecedented in terms of the density of fog. Many flights were diverted and scores were delayed at the Delhi airport due to dense fog.
“Fog issue is an issue that we encounter 15-20 days every year... This year, there has been unprecedented fog for the last three or four days. We are coordinating with all the airlines to make sure that they have CAT II and CAT III-trained pilots during fog hours, thereby easing congestion,” Scindia said. CAT II and III requirements pertain to operating flights in low visibility conditions.
The civil aviation ministry is monitoring the fog situation on a daily basis. He also said measures are being put in place, including monitoring congestion at a landing airport so that takeoff is not allowed if there is no direct routing, ensuring there is no congestion.
A Northern Railways spokesperson said that at least 11 trains were running late by more than one hour on Friday morning. As per the latest update, several trains, including Rajdhani Express on the Delhi-Howrah route, were delayed by 10 and 12 hours.
According to the IMD, after four days of dense to very dense fog, visibility improved in many parts of Delhi on Friday afternoon as most fog transformed into low clouds, indicating weakening of the lower-level stable boundary layer. The minimum temperature in Delhi was recorded at 10.7 degrees Celsius, four notches above the season’s average. Meanwhile, the city air continued to remain ‘very poor,’ with the average air quality index (AQI) at 332 around 9 am, settling at 382 at 4 pm.
Forecasts state that Delhi’s air quality is likely to remain ‘very poor’ till December 31. At the Anand Vihar area, PM2.5 levels remained in the ‘severe’ category standing at 473, and PM10 reached 447. The Indira Gandhi International (IGI) Airport T3 witnessed PM2.5 levels at 425 and PM10 at 405, both falling under the ‘severe’ category. Weather conditions are not favorable for the effective dispersion of pollutants. Emissions from firecrackers if burnt on December 31 will further deteriorate air quality… The predominant surface wind is likely to be from the east-southeast direction in Delhi-NCR with a wind speed of 6-4 kmph with partly cloudy sky with dense to very dense fog at most places in the morning on December 29,” the IITM’s air quality early warning system has predicted. The Met Department stated that fog conditions would not improve before January 2.
In an advisory for dense fog, the Met department has asked drivers to use fog lights and travelers to stay updated on schedules of airlines, railways, and state transport. “Exercise caution while driving or using any mode of transportation,” the IMD said.
