New Delhi: Chilly winds on Wednesday marked the arrival of cold wave conditions in the national capital as Delhi recorded a low of 4.9 degrees Celsius, the Indian Meteorological Department (IMD) said.

The minimum temperatures in early December have been recorded below 5 degrees Celsius for the first time in 14 years, it said.

According to data, the lowest minimum temperature during this period was recorded on December 6, 1987, at 4.1 degrees Celsius.

The IMD has issued a yellow alert, warning of similar cold wave conditions for the next two days.

The night-time temperature was recorded at 4.9 degrees Celsius on Wednesday, 4.7 notches below the normal. On Tuesday, it was 8 degrees Celsius.

According to the data, in December 2023 and 2022, there were no cold wave days. However, November 2020 saw cold wave conditions with the minimum temperature plunging to 7.5 degrees Celsius.

A cold wave occurs when the minimum temperature departures from the normal day temperature by 4.5 to 6.4 degrees Celsius. If the negative departure exceeds 6.4 degrees Celsius, it is classified as a “severe cold wave”.

The IMD has attributed the current sharp temperature drop to surface winds blowing from the northwest at 8-10 kmph.

The absence of significant western disturbances and strong surface winds during the day (10-20 kmph) are expected to keep minimum temperatures in the range of 4-6 degrees Celsius for the next three to four days.  Cold wave conditions are expected to prevail in Delhi between December 11 and 13.

On Wednesday, the city recorded a high of 23 degrees Celsius, 1.8 notches below the normal with the humidity fluctuating between 64 and 39 per cent.

A breezy day with wind blowing at a speed of 16 kmph along with a clear sky is expected on Thursday. Smog or mist is likely to appear in the evening or night.

The Air Quality Index (AQI) at 4 pm was 199 (moderate), according to the Central Pollution Control Board (CPCB).

The primary pollutants were PM2.5 and PM10, which pose serious health risks as they can penetrate deep into the lungs and enter the bloodstream.

Forecast suggests AQI to remain ‘poor’ in the capital for the next two days, according to the Air Quality Early Warning System for Delhi.