Cold wave conditions are predicted in parts of Delhi over the next four days as the minimum temperature is expected to drop to three to four degrees Celsius, the India Meteorological Department said on Tuesday.
Moderate to dense fog is also expected during the period, it said.
The Safdarjung Observatory, which provides representative data for the city, recorded a minimum of 5.3 degrees Celsius and a maximum of 23.9 degrees Celsius on Tuesday, the IMD said.
The observatory had recorded a minimum of 3.4 degrees Celsius on Sunday, the lowest this season so far.
The minimum temperature had increased slightly to 5.5 degrees Celsius on Monday under the influence of a fresh Western Disturbance (WD) affecting the upper reaches of the Himalayas.
The maximum temperature settled at 23.5 degrees Celsius, two notches more than normal.
After the WD withdraws on Tuesday, the temperatures are expected to drop again, Mahesh Palawat, an expert at Skymet Weather, a private forecasting agency, said.
The Western Disturbance led to light to moderate snowfall in the upper reaches of Jammu and Kashmir, Ladakh and Himachal Pradesh, he said.
Another Western Disturbance is likely to affect the upper Himalayan region from December 26, Mr. Palawat said.
For the plains, the IMD declares a cold wave when the minimum temperature is 10 degrees Celsius or below and is 4.5 notches less than normal for two consecutive days. However, for small areas such as Delhi, a cold wave can be declared if the criteria is fulfilled even for a day, officials said.
According to the IMD, very dense fog is when visibility is between 0 and 50 meters, 51 and 200 is dense , 201 and 500 moderate , and 501 and 1,000 shallow.
