A severe cold wave tightened its grip over north India on Monday, with mercury settling at 3.4 degrees Celsius in Delhi, and Leh town of Kashmir reeling at 18.2 degrees below the freezing point.

While the capital saw some respite from the chill during the day, with maximum temperature at 20.8 degrees Celsius, dense morning fog continued to disrupt train schedules. 

"There is a heavy backlog in trains, leading to many delays and rescheduling of trains," a Northern Railways spokesperson said.

"As many as 25 trains are running late and two services were rescheduled in the capital, where dense fog reduced visibility to 500 metres in the morning," the official said. As a precautionary measure, 31 long-distance trains have been partially cancelled as per an IANS report.

A Delhi International Airport Ltd (DIAL) spokesman told that no flights had been affected by fog on Monday.

The bone-freezing chill forced many to wrap themselves in layers of woollens. For the pavement dwellers, the only solace was bonfires they lit under trees and in parks.

In Punjab, Chandigarh recorded a minimum temperature of 3.4 degrees, three notches below average for this time of the season, while Amritsar shivered at minus 1.2 degrees - a whopping 5 degrees below average.

Ludhiana saw mercury plummet by seven notches to reach 0.2 degree.

Severe cold also claimed a life in Ambala, where an unidentified body, suspected to be of a beggar, was found near the Ambala Cantonment railway station, officials said.

A biting cold also affected people in Uttar Pradesh, with capital Lucknow recording a minimum temperature of 2.9 degrees Celsius, four notches below average.

Mercury dipped to 0.5 degree in Kanpur, while Agra shivered at 1 degree.

People emerged from their homes briefly in the afternoon to soak in the sun, but scurried back indoors once the evening set in and chilly winds started blowing.

Icy winds enveloped the snow-covered hills and swept down across most of Himachal Pradesh, many towns and areas recording sub-zero temperatures.

Shimla saw a some decline in night temperature at a low of 4.4 degrees Celsius from Sunday's 6 degrees, the weather office in Shimla said.

In Manali, the mercury slipped to minus 0.8 degree Celsius and in Solan to 2.7 degrees. However, Dharamsala was comparatively comfortable at 4.3 degrees Celsius.

Mercury continued to touch new lows in Jammu and Kashmir, with Srinagar recording a bone-chilling 4.9 degrees Celsius below the freezing point and Leh town literally frozen at a severe minus 18.2 degrees.

"Srinagar and Leh experienced the lowest temperatures of the season. Due to icy winds blowing into the Kashmir Valley, the minimum temperatures have been falling," said Sonam Lotus, director of the local meteorological office,.

The minimum was minus 8.4 in north Kashmir's ski resort of Gulmarg and minus 7.4 in south Kashmir's Pahalgam hill station.

"Severe cold wave conditions will continue for four to five days. However, due to a feeble approaching disturbance we might get a degree's rise in the minimum temperatures. But we do not expect any rain or snow for now," Lotus said.

IANS