A blinding layer of fog over north India and eastern parts of the country affected the schedule of over 480 trains and over 25 flights on Sunday even as an intense cold wave walloped the plains, including Delhi, where the minimum temperature plunged to a numbing 1.9 degrees Celsius.
Delhi’s minimum temperature was lower than most places in Himachal Pradesh and Uttarakhand — both north of the national capital– for the fourth consecutive day. The cold snap, which is straining power grids and posing challenges to the homeless and animals, prompted the Delhi government to extend winter vacation in schools till January 15.
The India Meteorological Department (IMD) has issued an “orange” alert for certain parts of north India, including Delhi, for Monday, warning that dense fog, cold day and cold wave conditions would persist.
A senior IMD meteorologist said short-term relief is likely after a couple of days under the influence of back-to-back western disturbances.
When a Western disturbance — a weather system characterised by warm moist winds from the Middle East — approaches a region, the wind direction changes. Hence, the chilly northwesterly winds from the mountains will stop blowing for a few days leading to an increase in temperatures, he said.
“Cold wave and cold day conditions over northwest India (are) likely to abate after 48 hours. Dense to very dense fog conditions over many parts of Punjab, Haryana, Delhi, Uttar Pradesh and Bihar (are likely) during the next 48 hours and decrease in intensity and distribution thereafter,” the IMD said in a statement.
A dense layer of fog persisted over north, east and northeast India, affecting road, rail and air traffic movement.
“Around 335 trains have been delayed, 88 cancelled, 31 diverted and 33 short terminated due to foggy weather,” a railway official said.
Around 25 flights were delayed and two diverted Sunday morning, officials at the Indira Gandhi International Airport said.
Visibility levels dropped to zero metres at Bhatinda and Agra; 25 metres at Patiala, Chandigarh, Hissar, Alwar, Pilani, Ganganagar, Lucknow and Cooch Behar; 50 metres at Amritsar and Ludhiana, Ambala, Bhiwani, Palam (Delhi), Fursatganj, Varanasi, Meerut, Gaya and Dhubri.
According to the weather office, ‘very dense fog’ is when visibility is between 0 and 50 metres, between 51 and 200 metres is ‘dense’, between 201 and 500 metres ‘moderate’, and between 501 and 1,000 metres ‘shallow’.
A severe cold wave hit Delhi, with the minimum temperature at the Safdarjung observatory, the city’s primary weather station, plunging to 1.9 degrees Celsius, the lowest in January in two years.
With frosty winds from the snow-clad mountains pounding northwest India, the weather stations at Lodhi Road, Ayanagar, Ridge and Jafarpur logged a minimum temperature of 2.8 degrees, 2.6 degrees, 2.2 degrees and 2.8 degrees Celsius, respectively.
It was the fourth day on the trot that the national capital’s minimum temperature was lower than most of the hill stations in Himachal Pradesh and Uttarakhand, including Chamba (8.2 degrees), Dalhousie (8.2 degrees), Dharamshala (6.2 degrees), Shimla (9.5 degrees), Hamirpur (3.9 degrees), Manali (4.4 degrees), Kangra (7.1 degrees), Solan (3.6 degrees), Dehradun (6 degrees), Mussoorie (9.6 degrees), Nainital (6.2 degrees), Mukteshwar (6.5 degrees) and Tehri (7.6 degrees), according to the IMD.
The Safdarjung observatory had logged a minimum temperature of 2.2 degrees Celsius on Saturday, 4 degrees Celsius on Friday, 3 degrees Celsius on Thursday and 4.4 degrees Celsius on Wednesday. A severe cold wave had brought the minimum temperature down to 1.5 degrees Celsius at the Ridge weather station in central Delhi on Saturday.
The mercury dropped to 1.4 degrees Celsius in Haryana’s Hisar, 2.8 degrees Celsius in Punjab’s Adampur, minus 0.5 degree Celsius in Churu and 1.5 degrees Celsius in Pilani in Rajasthan; 3.2 degrees Celsius in Prayagraj and 3.8 degrees Celsius in Varanasi in Uttar Pradesh; 2.9 degrees Celsius in Gaya in Bihar; minus 1 degree Celsius in Nowgong and 1.5 degrees Celsius in Umaria in Madhya Pradesh, the IMD said.
Cold day to severe cold day conditions prevailed over parts of Uttar Pradesh, Bihar and Haryana with the maximum temperature settling at least 6.5 degrees Celsius below normal, the weather bureau said.
The IMD warned of an impact on agriculture, livestock, water supply, transport and the power sector at some places.
The weather office also said frostbite can occur due to a prolonged exposure to cold and that one should not ignore shivering — the first sign that the body is losing heat — and should stay indoors.
“Eat vitamin C-rich fruits and vegetables and drink sufficient warm fluids to maintain adequate immunity. Avoid or limit outdoor activities,” it said in an advisory.
In the plains, the MeT office declares a cold wave if the minimum temperature dips to 4 degrees Celsius or when it is 10 degrees Celsius and 4.5 notches below normal.
A severe cold wave is when the minimum temperature dips to 2 degrees Celsius or the departure from the normal limits is by more than 6.4 notches. A cold day is when the minimum temperature is less than or equal to 10 degrees Celsius and the maximum temperature is at least 4.5 notches below normal.
A severe cold day is when the maximum temperature is at least 6.5 notches below normal.