New Delhi, Jan 15 (IANS): India Meteorological Department (IMD) has forecast a cold day for Delhi with the maximum and minimum temperatures dipping to 16 and 6 degrees Celsius respectively, this morning.

Meanwhile, due to fog, the visibility at Palam was reduced to 600 meters at 6.30 a.m. The relative humidity at 8.30 a.m. stood at 100 per cent.

As per IMD, the next six days will be densely to moderately foggy with the possibility of light rain on January 19 and 21.

Dense/very dense fog in some/isolated pockets in night/morning hours is very likely over Delhi during the next three days, the IMD bulletin said.

The maximum and minimum temperatures will hover around 18 and 8 degrees Celsius. With a maximum temperature dipping to 15.4 degrees Celsius -- five notches below normal, Delhi recorded a cold and longest foggy day on Friday.

The city's minimum temperature was recorded at 6 degrees Celsius -- a degree below the normal.

As per IMD, there was a layer of dense fog in the morning and moderate fog during the day over Delhi NCR, also over Punjab, Haryana, west UP & north Rajasthan preventing sunlight from reaching the surface. Also, light north westerlies are blowing over the region. These conditions led to cold days.

Delhi's Air Quality Index at 10 a.m. stood at 312, as per System of Air Quality and Weather Forecasting And Research's (SAFAR) estimates.

The level of both PM 2.5 and PM 10 pollutants stood in the 'very poor' and 'moderate' categories, respectively.

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', then 401 and between 500 is considered 'severe.'

According to the weather bulletin, the air quality is likely to remain in the lower end of the very poor category on January 16 and 17.

The air quality is likely to remain largely in the poor to lower end of very poor category, the next five subsequent days.