According to the IMD, verydensefogis when visibility is between 0 and 50 metres, 51 and 200 is dense, 201 and 500 moderate, and 501 and 1,000 shallow.
The minimum temperature was three notches below normal. The maximum temperature is likely to settle around 19 degrees Celsius, it said, predicting 'cold day' conditions at a few places.
The IMD had declared a cold wave in Delhi on Tuesday as icy winds blowing from snow-covered western Himalayas brought the minimum temperature down to 4.1 degrees Celsius, the lowest in the city this season so far.
The maximum temperature had also dipped to 18.5 degrees Celsius, more than four notches below normal.
According to the IMD, the minimum temperatures is likely to remain around five degrees Celsius till Friday.
Kuldeep Srivastava, the head of the IMD's regional forecasting centre,said the Western Himalayas recorded widespread snowfall due to strong Western Disturbances and now frosty winds have been blowing towards the plains, bringing the mercury down.
He saidboth "cold wave" and "cold day" conditions are likely in Delhi on Thursday and Friday.
For the plains, the IMD declares acoldwavewhen 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, acoldwavecan be declared if the criteria is fulfilled even for a day, Srivastava said.
A cold day is when the minimum temperature is less than 10 degrees Celsius and the maximum is 4.4 degrees Celsius below normal.
The air quality was recorded in the "poor" category.
The city's air quality index (AQI) was 278 at 9 am. The 24-hour average AQI was 230 on Tuesday. It was160 on Monday, 305 on Sunday and 356 on Saturday.
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".
(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.