Delhi witnessed the coldest New Year's Day with mercury dropping to 1.1 degrees Celsius, the lowest in 15 years. A "very dense" fog covered the skies and the visibility was reduced to "zero" metres, affecting traffic movement.
The city recorded a minimum of 0.2 degrees Celsius on January 8, 2006.
Kuldeep Srivastava, the head of IMD's regional forecasting centre, told PTI that "very dense" fog lowered visibility to "zero" metres at Safdarjung and Palam at 6 am.
The Safdarjung Observatory, which provides representative data for the city, recorded a minimum of 1.1 degrees Celsius, the lowest in January in 14 years.
The lowest minimum temperature recorded in January last year was 2.4 degrees Celsius, the India Meteorological Department (IMD) said.
Delhi recorded a minimum of 3.3 degrees Celsius on Thursday. At 15.2 degrees Celsius, the city recorded the season's lowest maximum temperature on December 18.
Srivastava said the minimum temperature will start rising under the influence of an "intense" western disturbance which will affect northwest India from January 2 to January 6.
The minimum temperature is predicted to rise to 8 degrees Celsius by January 4-5.
Light rain is also expected in the national capital under the influence of the western disturbance from January 3 to January 5.
The western disturbance will lead to moderate snowfall in the western Himalayan region, the IMD said.
In the plains, the weather department has declared a cold wave if the minimum temperature dips to 4 degrees Celsius. A severe cold wave is when the minimum is 2 degrees Celsius or less.
The average minimum temperature in Delhi in December was the second-lowest in 15 years.