Delhi saw the coldest January day in nine years on Tuesday, with the maximum temperature plunging 10 degrees below normal and settling at 12.1 degrees Celsius, the India Meteorological Department said.
It was also the second consecutive "severe cold day" in the capital.
The cold was so intense that all weather stations in Delhi recorded their maximum temperatures 10 to 11 degrees Celsius below normal.
The Safdarjung Observatory, which provides representative data for the city, recorded a maximum temperature of 12.1 degrees Celsius, which was the lowest on a January day after 9.8 degrees Celsius recorded on January 3, 2013, according to IMD officials.
Senior IMD scientist RK Jenamani said it was also the lowest maximum temperature of the season so far.
Palam (11.6 deg C), Lodhi Road (12.2 deg C), Ridge (11.7 deg C), Ayanagar (12 deg C), Jafarpur (11.4 deg C), Najafgarh (12.5 deg C), Narela (11.7 deg C), Pitampura (13.1 deg C), Sports Complex (13.7 deg C) and Mayur Vihar (11.9 deg C) recorded a severe cold day.
According to independent weather forecaster Navdeep Dahiya, the average maximum temperature for all the 18 stations in the national capital regions was 12 degrees Celsius.
Delhi had recorded a severe cold day on Monday as well.
According to the IMD, a "cold day" is when the minimum temperature is less than 10 degrees Celsius and the maximum is at least 4.5 degrees Celsius below normal.
A "severe cold day" is when the maximum temperature is at least 6.5 notches below normal.
According to the IMD data, the capital has recorded six cold days in January so far, the highest in the month in at least a decade.
Jenamani said Delhi has recorded a maximum temperature of less than 17 degrees Celsius on 11 days this month, equalling the number of such days in 2015.
Eighteen such days were recorded in 2003, he said.
The maximum temperatures have been lower than normal since the second week of January. Minimum temperatures have been close to or above normal.
This is largely due to clouds and rain preventing long exposure to sunshine, according to Mahest Palawat, Vice President (Meteorology and Climate Change), Skymet Weather.
There have been seven Western Disturbances in Delhi this January as against a normal of three to four in the month.
The rains due to the western disturbances increased moisture in the air, which led to foggy conditions amid low temperatures on most of the days, Palawat said.