Cold wave conditions likely in Delhi over next 4 days: IMD

New Delhi, Dec 22: 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 predicted during the period, it said.

The Safdarjung Observatory, which provides representative data for the city, recorded a minimum of 5.3 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 WD 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, 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.

The air quality was recorded in the "very poor" category.

The city''s air quality index (AQI) was 365 at 9 am. The 24-hour average AQI was 332 on Monday and 321 on Sunday.

An AQI between zero and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".