New Delhi, Dec 15 (IANS): The national capital on Tuesday recorded the lowest minimum temperature of the season so far with mercury dipping to 4.1 degrees Celsius, four notches below the normal. Jafarpur in southwest Delhi was the coldest at 3.6.

This is a massive dip as the capital city had, on Monday recorded a minimum temperature of 8.4 degrees Celsius after 11.4 on Sunday and 14.4 degrees Celsius on Saturday, respectively.

A dip of 10 degrees in four days. In 1930 on December 27, Delhi had recorded zero degree, according to private weather agency Skymet.

"Cold wave over Delhi," confirmed Mahesh Palawat of private weather forecasting agency Skymet Weather.

The India Meteorological Department announces the cold wave when the minimum temperature is 10 degrees or below and is 4.5 notches less than the normal for two consecutive days.

The Safdarjung Observatory, which provides the representative data for the city, recorded a minimum temperature of 4.1 degrees Celsius, while Lodhi Road, Ayanagar and Jafarpur Observatory recorded it at 4.2, 4.0 and 3.6 degrees Celsius.

Delhi's air quality remained in the "moderate" category due to favourable wind speed. The city's air quality index (AQI) was 192 at noon. On Sunday, the average 24-hour AQI in the national Capital stood at 162.