Delhi residents woke up on Sunday to the chilliest November morning in the last 17 years, with minimum temperature clocking a low of 6.4 degrees Celsius at Lodhi Road, officials of India Meteorological Department (IMD) told IANS.

It's closest to the record set on November 29, 2003 when the mercury dipped to 6.1 degrees.

However, Safdarjung recorded a dip in temperature to 6.8 degrees. The officials said that isolated places like Lodhi Road reported temperature falls below the average taken by the IMD. Meanwhile, the maximum temperature on Sunday is expected to be 24 degrees on Sunday, the IMD officials added.

Kuldeep Srivastava, scientist at the IMD and head, regional weather forecasting centre, had earlier told IANS that Sunday could also witness the coldest night of the month. He had said that chilly winds raging after snow in Himalayan states could bring the mercury down to 7 degrees.

"As the wind direction continues to be north-westerly, cold winds are coming from Jammu and Kashmir and Himachal Pradesh, which received snow. Besides, clear skies in the day cause heat to dissipate quickly and make nights cooler than usual," Srivastava had explained.

However, Srivastava also forecast that the temperature is expected to rise for the next three-four days to drop again after November 27. "Western Disturbance and the change in wind direction will lead to rise in temperature," he added.

The minimum temperature in the national capital dropped to 7.5 degrees Celsius on Friday morning, five notches below normal for this time of the year. As per IMD officials, this was the lowest minimum temperature recorded in November since 2006.

According to IMD scientists, the minimum temperature does not usually drop below 10 degrees Celsius in November. They attributed the fall to the combination of cold winds and clear sky in Delhi.

"It's unusual for the minimum temperature to drop to single digits in mid-November. Winter is setting in early this year. The sharp drop in night temperature is mainly because of a combination of cold winds blowing from the snow-clad western Himalayan region as well as largely clear skies in Delhi. When there is no cloud cover, the heat trapped in the ground dissipates fast, resulting in lower temperatures," Srivastava said.

On Thursday, the city had recorded a minimum temperature of 9.4 degrees. In 2017, the minimum temperature had dipped to 7.6 degrees in the last week of November. The lowest temperature recorded last November was 11.4 degrees, and in 2018 10.5 degrees Celsius.

Meanwhile, the city's air quality index fell into the "poor" category on Saturday with a reading of 252. The System of Air Quality and Weather Forecasting And Research (SAFAR), the forecasting body under the Union Ministry of Earth Sciences said 1,264 fire counts were observed in neighbouring states and the share of stubble-burning in Delhi's PM2.5 is expected to be 13 per cent on Sunday.