PHOTOS: North India shivers, season's coldest day in Delhi

It was the coldest December 22 in the last five years with mercury dropping to the season's lowest of 4.2 degree Celsius on Monday, even as a thick blanket of fog severely hit flight and train operations besides affecting vehicular movement

According to the MeT department, the minimum temperature was four notches below normal and dropped 2.2 degrees from Sunday’s 6.4 degrees Celsius. The maximum temperature was recorded at 15.8 degree Celsius, which too was six degrees below normal.

As many as 173 flights were delayed and around 70 north-bound trains were affected as dense fog stalled operations at the airport and railway stations -- the first major disruption this winter season.

On Sunday, the morning temperature had settled two points below the season's average at 6.4 degrees Celsius.

Dense fog enveloped the national capital with visibility dropping to zero in the early hours. However, visibility improved to 150 metres by 9 am.

According to the local meteorological department, most places across the state were affected by fog with snowfall in neighbouring Uttarakhand further intensifying the cold conditions in UP.

"The minimum temperature was recorded at 4.2 degree Celsius. It is the coldest December 22 in the last five years. It is also the coldest day of this season," said a MeT official.

In the morning, dense fog enveloped the city with visibility dropping to zero in the early hours. However, visibility improved to 150 metres by 9 am. Around 70 north-bound trains, including Rajdhani Express coming from Kolkata, Ranchi, Bhubneshwar, Sealdah, Magadh.

Lichhvih and Purshuttom Express were running late by several hours due to the dense fog. Traffic moved slowly due to foggy conditions and there were traffic jams in several areas.

Traffic moved slowly due to foggy conditions but there were no major traffic jams, said a senior traffic police official.

With intense cold conditions continuing to prevail across Uttar Pradesh, the state government ordered closure of all the schools upto class eight till December 28, officials said.

Weatherman said that things will improve by the afternoon. The day temperature may settle around 14 degree Celsius.

Cold weather conditions continued to prevail at most places in Punjab and Haryana as well, where fog threw normal life out of gear. Karnal in Haryana was the coldest place in the state recording a minimum temperature of 3.6 degrees Celsius, four notches below normal.

Hisar also reeled under cold conditions recording a low of 5.6 degrees Celsius, one notch below normal, while biting cold also prevailed at Narnaul, where the low settled at 4 degrees Celsius, down two notches.

Two persons died in Badaun and several others were injured when a tractor trolley collided with a Delhi-bound bus due to dense fog in Sahaswan area.

In another case, 14-year-old boy Sushil was killed in Barabanki district after being hit by a bus due to dense fog.

Night temperatures dipped at many places in Varanasi, Faizabad, Allahabad, Meerut and Gorakhpur.

The mercury level stayed below normal in most of the places including Varanasi, Meerut, Gorakhpur, Faizabad, Allahabad, Moradabad, Lucknow and Agra.

The minimum temperature in the state was recorded in Meerut at 2.3 degrees Celsius.

The fog has affected train and air traffic with flights and trains running several hours behind schedule. 

Ambala also experienced a cold night at 5.8 degrees Celsius, the MeT Department said.

Chandigarh's night temperature settled at 7.6 degrees Celsius. In Punjab, Amritsar recorded a low of 5.4 degrees Celsius, while Patiala's minimum settled at degrees Celsius, down two notches. Ludhiana's minimum settled at 7.8 degrees Celsius.

In Jammu and Kashmir, Chillai-Kalan, 40 days of harshest winter period, started on Sunday increasing the chances of first snowfall of the season in the Kashmir Valley which has seen dry weather so far.

One person died of the cold in UP on Sunday. In Delhi, three people died of suffocation after they lit a coal fire to keep their home warm.

The meteorological department forecast says that Tuesday will be dry and fog would occur at many places over the state.

The weatherman has warned of dense to very dense fog at a few places.