The national capital shivered on a severe cold day on Tuesday as its minimum temperature fell below that of Dehradun, Dharamsala and Nainital.
With a high windchill factor -- a measure of the rate of heat loss from skin that is exposed to the air -- in play, the weather office predicted a cold day.
The Safdarjung observatory, Delhi's primary weather station, logged a minimum temperature of 5.6 degrees Celsius -- a notch below normal. The maximum temperature was predicted to settle around 16 degrees Celsius.
In comparison, the minimum temperature in Dehradun was recorded at 7 degrees Celsius, Dharamsala at 6.2 degrees Celsius and Nainital at 7.2 degrees Celsius.
Meteorologists attributed the sharp drop in day temperatures to frigid north westerly winds barrelling through the plains and reduced sunshine due to foggy weather.
Mahesh Palawat, vice president (meteorology and climate change) at Skymet Weather, said a western disturbance led to a fresh spell of snowfall in the mountains on December 25-26 and cold northwesterly winds were sweeping through the plains after its retreat.
The sun was blotted out in large swathes of northwest India as dense to very dense fog prevailed in some parts of the National Capital Region, Haryana, Punjab, west Uttar Pradesh and north Rajasthan.
In the national capital, visibility fell to just 50 metres and affected road traffic and train movement.
Fog shrouded many parts of Punjab and Haryana where intense cold weather conditions continued on Tuesday.
In Haryana, Narnaul shivered at one degree Celsius, four degrees below normal, according to a report of the Met centre here. In Punjab, Bathinda experienced cold weather conditions at 1.4 degrees Celsius. Amritsar recorded a low of 5 degrees Celsius while Ludhiana's minimum was 6.6 degrees Celsius. Severe cold conditions prevailed in Rajasthan as well. However, the regional weather office has predicted the possibility of a slight increase in the minimum and the maximum temperatures from Wednesday.
Coldwave conditions gripped Kashmir as the mercury fell by a couple of degrees across the Valley to push the minimum temperature further below freezing point, officials said. The minimum temperature on Monday night fell by one to two degrees compared to the previous night.
The intense cold led to water supply lines freezing in several areas. The interiors of Dal Lake and several other water bodies in the Valley also froze, the officials said. The minimum temperature in Srinagar settled at minus 4.8 degrees Celsius -- down from minus 3.5 degrees Celsius on Sunday night. According to the India Meteorological Department (IMD), 'very dense' fog is when visibility is between 0 and 50 metres, 51 and 200 metres is 'dense', 201 and 500 'moderate', and 501 and 1,000 'shallow'.
In the plains, the IMD declares a cold wave if the minimum temperature dips to four degrees Celsius or when the minimum temperature is 10 degrees Celsius or below and is 4.5 notches below normal.
A 'severe' cold wave is when the minimum temperature dips to two degrees Celsius or the departure from normal is more than 6.4 degrees Celsius.