As thick fog engulfed most parts of north India on Tuesday, poor visibility affected air and train traffic causing delays, diversions and cancellations inconveniencing travellers.
Operations at Indira Gandhi International (IGI) Airport in Delhi came to a standstill as dense fog engulfed the city for the second consecutive day, affecting around 80 domestic and international flights.
Kapil Sabarwal, spokesperson of IGI Airport, said: "Many international and domestic flight landings were delayed Tuesday morning because of the dense fog that created a major visibility problem."
The fog became dense around 5am and the visibility went below 50 metres, the minimum required for landing under poor visibility conditions using the CAT-III B instrument landing system (ILS).
The minimum visibility for an aircraft to take off under low visibility conditions are between 125 to 150 metres, depending on the size of the plane.
On Monday, schedules of around 140 flights were hit after Delhi witnessed the winter's first fog. Nine flights were diverted while eight were cancelled.
Fog started to descend upon Delhi around midnight and engulfed the entire city by Tuesday morning, reducing the general visibility to almost zero, officials of the India Meteorological department said.
According to a senior weather official Delhi and the National Capital Region will witness fog or dense fog till forenoon during the week, and a partly cloudy sky on Saturday and Sunday.
The Met office also said that it will also affect a number of states stretching from Punjab to Bihar.
The minimum temperature in Delhi on Tuesday was recorded one notch above the season's average at nine degrees Celsius, an official said.
"A western disturbance was likely to affect western Himalayan region and adjoining plains from Saturday onwards. This would result in light rain or snowfall at a few places over Jammu and Kashmir, Himachal Pradesh and at one or two places over Uttarakhand between December 21 and 24," said OP Singh, deputy director general of meteorology, regional meteorological centre, New Delhi.
Light rain or thundershower are expected at one or two places over Punjab and northern Rajasthan on Sunday.
"Over Delhi- NCR fog or dense fog would prevail till forenoon during the period, with partly cloudy sky mainly on December 21 and 22. The minimum temperature would be between 7 and 9 degree C and the maximum temperature is likely to remain between 20 and 23 degree C over Delhi NCR," Singh said.
Road traffic also bore the brunt of the poor visibility, as vehicles moved extremely slowly in most parts of Delhi till around 11am, after which the fog dissipated away slowly.
Rail traffic was also hit because of low visibility and many trains were rescheduled on account of late arrival of trains coming to the national capital.
"Trains arrival and departures were delayed as visibility was poor...," AS Negi, a Northern Railway spokesperson said.
Railways had earlier announced cancellation of some trains to efficiently tackle train movement during foggy weather conditions.
"Passengers can contact (Delhi telephone number) 23747110, the new helpline number started by the Northern Railway," he said.
The latest position of the affected trains are being updated regularly on the railway website, the spokesperson said.
Many states affected
Punjab, Haryana, Uttar Pradesh and northwest Rajasthan also came under the fog causing disruption to air and rail travel.
In Punjab, fog and mist reduced visibility to less than 50 metres at several places, including Patiala, Amritsar, Hisar, Karnal Ambala and Ludhiana. Low visibility also hit flight operations in Chandigarh and Amritsar.
"No flight took off today as there was zero visibility due to fog," Amritsar airport director Suneel Dutt said.
Morning flights from Delhi to Chandigarh are behind their scheduled arrival timings because of fog, officials at Chandigarh airport said.
Fog also cast a shadow on rail traffic at Chandigarh as departure of several trains, including the Shatabdi (New Delhi Kalka), Himalayan Queen and Bhiwani-Kalka were delayed by one and a half hours while arrival of few trains, including Allahabad-Chandigarh train was delayed by nine hours.
Adampur in Punjab turned out to be the coldest place in the region as it recorded a minimum temperature of 2.2 degree Celsius, Met department officials said.
Met department in its forecast said fog and mist will prevail during morning and night in Punjab and Haryana.
One person was killed and 20 others injured when a bus collided with a truck in Tarwan area of Azamgarh in Uttar Pradesh because of dense fog, police said.
Truck driver Ram Awadh Yadav (40) was killed when his vehicle collided with the bus near Dheerdhar village in the morning, they said.
(With inputs from PTI)