Explained: Why Delhi is witnessing a dip in temperature?

New Delhi, Dec 16: The national capital was on Wednesday covered with dense fog as it recorded a minimum temperature of 5.8 degrees Celsius in the morning, three notches below the normal temperature. Meanwhile, the India Meteorological Department (IMD) has predicted "cold day and cold wave" in parts of Delhi on Thursday and Friday.

On Tuesday, the minimum temperature in New Delhi dropped to 4.1 degrees Celsius, the lowest during the season this year. The dip was five degrees below the normal temperature for this time of the year.

What is causing the dip in Delhi's temperature?

The question about what is causing the dip in the temprature is due to a significant amount of snowfall over the past few days in states falling in the western Himalayan range.

"In winters, whenever an active Western Disturbance passes through the western Himalayan region, it leads to a dip in temperatures across northwest India," said Kuldeep Srivastava, head of the IMD's regional weather forecasting centre.

A Western Disturbance, labelled as an extra-tropical storm originating in the Mediterranean, is an area of low pressure that brings sudden showers, snow and fog in northwest India.

"Snowfall in the western Himalayan range means cold, north-westerly winds blowing over Delhi from the direction of this high altitude area, and clearing of cloud cover with the passing of Western Disturbance, and leads to a fall in temperatures," said Srivastava.

On December 12, a rapid decline in minimum temperature in Delhi was noted from 14.4 degrees when the city witnessed light rainfall, to 4.1 degrees on Tuesday.

The lack of cloud cover also leads to higher radiation from the Earth's surface into the atmosphere at night time, which also cools the ground, Srivastava said.