In the plains, the IMD declares 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 IDM said the mercury may drop further by New Year's Eve.
Cold wave conditions are predicted in parts of the city over the next three days, it said.
Kuldeep Srivastava, the head of the regional forecasting centre of the IMD, said a western disturbance led to "scattered to fairly widespread" snowfall in Jammu and Kashmir, Ladakh, Himachal Pradesh and Uttarakhand.
Cold and dry northerly/northwesterly winds from the western Himalayas have been barrelling through the plains, bringing the minimum temperature in north India down, he said.
On December 20, the Safdarjung Observatory had recorded a minimum of 3.4 degrees Celsius, the lowest this season so far.
Delhi's air quality was recorded in the "poor" category on Tuesday morning. The city's air quality index (AQI) was 237 at 9 am.
The 24-hour average was253 on Monday, 396 on Sunday,337 on Saturday, 357 on Friday, 423 on Thursday and 433 on Wednesday.
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".
Officials at IMD said favourable wind speed, up to 15 kmph, aided in dispersion of pollutants.
(Only the headline and picture of this report may have been reworked by the Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)
Business Standard has always strived hard to provide up-to-date information and commentary on developments that are of interest to you and have wider political and economic implications for the country and the world. Your encouragement and constant feedback on how to improve our offering have only made our resolve and commitment to these ideals stronger. Even during these difficult times arising out of Covid-19, we continue to remain committed to keeping you informed and updated with credible news, authoritative views and incisive commentary on topical issues of relevance.
We, however, have a request.
As we battle the economic impact of the pandemic, we need your support even more, so that we can continue to offer you more quality content. Our subscription model has seen an encouraging response from many of you, who have subscribed to our online content. More subscription to our online content can only help us achieve the goals of offering you even better and more relevant content. We believe in free, fair and credible journalism. Your support through more subscriptions can help us practise the journalism to which we are committed.
Support quality journalism and subscribe to Business Standard.