LAHORE, Jan 1: A canopy of thick fog hung over the plains of Punjab including Lahore on Thursday, aggravating the chilly conditions on the New Year's Day.

Parts of the NWFP, the Northern Areas and Islamabad division received light rain and snow over the hills. In Lahore, it was the coldest day of the season as persistent fog reduced day's maximum temperature to 10 degrees Celsius - a record low for the season. It had been 21.2 degrees on Wednesday.

The minimum temperature was six degrees Celsius. The canopy of fog hung over the city the whole day. Attendance in offices was thin and the presence of people at city's recreational places and parks almost nil.

The prices of fish, dry fruit and new and used warm clothes sky-rocketed because of demand. The fog had started developing in the city at around 11pm on Wednesday night. It thickened after midnight, reducing visibility to a maximum of 300 metres at 7am. The visibility was 600 meters at 9am and improved to one kilometre at 1pm.

According to Chief Meteorologist Shaukat Ali Awan, the canopy of fog covered the Punjab plains up to Bahawalnagar, Mianwali and Faisalabad. It extended up to New Delhi in India.

The fog covered a vast area because of low temperature, high humidity, light wind and stagnant upper air. Rain in the Northern Areas added to the humidity, Mr Awan said, adding that the weather conditions would start improving only in the second week of this month.

"This is the peak of winter season, giving a cold punch to the (poor) people as New Year's gift," he said. The fog had first descended on Lahore during the current winter season on Dec 19, but it was washed away by light rain after a few days.

The Met office reported 6mm of rain in Kalam, Garhi Dupatta, 4mm in Dir, 3mm in Chitral and Murree, 2mm in Kotli, Kakul and Islamabad and 1mm in Balakot, Malamjabba and Saidu Sharif.

It has predicted fairly widespread thunderstorms and rain with snowfall over the hills in the Rawalpindi division and scattered rainfall in Lahore, Gujranwala, Sargodha, and Faisalabad divisions during the next 24 hours.

Parachinar was the coldest place in the country on Thursday with a minimum temperature of -8 degrees Celsius. The minimum temperature was -7 degrees Celsius in Kalam, -5 in Quetta, -4 in Malamjabba, Skardu and Murree and -3 in Astore.