Cold wave to severe cold wave conditions are very likely to continue in northwest India over the next two days and abate thereafter, the India Meteorological Department (IMD) said on Monday.

Cold wave conditions will continue over central and east India for the next three days and relief is likely thereafter, it said.

In the plains, the IMD declares a cold wave if the minimum temperature dips to 4 degrees Celsius. A cold wave is also declared when the minimum temperature is 10 degrees Celsius or below and is 4.5 notches less than 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.

"Cold wave to severe cold wave conditions are very likely to continue in some parts of Punjab, Haryana, Delhi, Rajasthan and Madhya Pradesh during the next 24 hours and cold wave conditions are very likely at isolated pockets for the subsequent 24 hours," the IMD said in a bulletin released at 1:45 pm.

Cold wave conditions are very likely over parts of Uttarakhand, Uttar Pradesh, Maharashtra, Bihar and Jharkhand till Wednesday afternoon and over Jammu, Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad, Himachal Pradesh, Gangetic West Bengal till Tuesday afternoon and are very likely to abate thereafter.

A cold wave is also predicted in parts of Chhattisgarh and Odisha till Thursday afternoon, the weather office said.

"Cold day to severe cold day conditions (are) very likely at some places over Madhya Pradesh and cold day conditions in isolated pockets over West Uttar Pradesh during the next 24 hours," the bulletin stated.

When the minimum temperature is less than or equal to 10 degrees Celsius and the maximum temperature is at least 4.5 degrees Celsius below normal, it is said to be a cold day.

"Under the influence of two Western Disturbances in quick succession, the first from December 22 and second from December 24, light to moderate rainfall and snowfall is likely over western Himalayan region from December 22 to 25. Light isolated rainfall is also likely over Punjab on December 24," the bulletin read.

Dense fog is predicted in the morning hours in parts of Punjab and Haryana from December 23 to December 25 and over western Rajasthan on December 24 and 25.

According to the IMD, when visibility is between 0 to 50 metres it is very dense fog, 51 and 200 metres is dense, 201 and 500 metres is moderate, and 501 and 1,000 metres is shallow.