On the first day of the New Year, the air quality index of the national capital was recorded in the 'very poor' category on Saturday morning with the AQI clocking 347 at 9 am, Central Pollution Control Board (CPCB) data showed.

The Delhiites woke up to a cold morning with the minimum temperature settling at 4.2 degrees Celsius, three notches below normal, according to the India Meteorological Department (IMD).

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'.

The city is expected to see mainly clear sky, and the maximum temperature may reach up to 20 degrees Celsius, the weather department said.

The relative humidity was 88 per cent at 8.30 am.

The IMD has forecast cold wave to severe cold wave conditions in northwest India till January 3.

A "severe" cold wave is when the minimum temperature dips to 2 degrees Celsius or the departure from normal is more than 6.4 degrees Celsius.