New Delhi, Jan 8 (IANS): The national capital recorded a minimum temperature of 9.6 degrees Celsius on Friday, a drop by five notches from 14.4 degrees Celsius logged a day before, according to the India Meteorological Department (IMD).

Safdarjung Observatory, which provides representative data for Delhi, recorded a minimum temperature of 9.6 degrees Celsius. The same temperature was recorded at Lodhi Road, followed by 10.3 degrees Celsius at Ridge, 10.5 at Ayanagar and 11.2 at Palam.

"There is a fall in temperature as a layer of cloud is not allowing the sunlight to pass through its surface, north-westerly winds have started and western disturbance has passed," Kuldeep Srivastava, head of the IMD's regional forecasting center told IANS.

The weather scientist further said there will be no variation in the minimum temperature for a few days and the mercury will start to fall from January 11 onwards. "On January 11-12, it will fall to 6-7 degrees Celsius," Srivastava added.

He said that there will be light rainfall "here and there" in the national capital and surrounding regions on Friday night. Delhi had witnessed rainfall for four consecutive days till Wednesday.

There will be gradual fall in minimum temperatures by 3-4 degree Celsius over most parts of Northwest India during the next three-four days. Cold wave conditions are likely over Punjab, Haryana and Rajasthan during January 8 and 9, IMD said.

Meanwhile, Delhi's air quality remained in the "poor" category due to favourable wind speed. The city's air quality index (AQI) was 218 at noon.

"Surface winds are calm, however, forecasted to improve gradually for the next few days. The improved ventilation condition is likely to influence AQI positively for the next few days," said System of Air Quality and Weather Forecasting and Research in a statement.