People wear their winter wardrobes to keep warm on the streets of Beijing on Thursday. [China Daily]

Both snow and the temperature are expected to fall over the weekend, threatening to keep air and road travel in the disorderly state they have been in during the current cold snap in North China.

The mercury is predicted to drop by up to 14 C in central and northern parts of the country, the China Meteorological Administration said on Thursday.

The National Meteorological Center has issued a blue alert, the lowest level in a four-tier warning system.

Some places may see their coldest December in years. The temperature in Beijing is expected to hit a 10-year low of -15 C on Saturday night. In the past three decades, the lowest December temperature recorded in the capital came in 1985, when thermometers registered -15.2 C.

"The cold snap will ease off in the capital on Monday, although another spell is expected on Dec 27 and 28," Song Jisong, chief forecaster of the Beijing Meteorological Bureau, said on Thursday.

Elderly people and infants should avoid spending a lot of time outdoors over the weekend, he said.

Lu Zining, 3, was dressed in five layers of clothes and was eating steamed glutinous rice with his mother to keep warm on his way to kindergarten on Thursday.

"I don't know what else he could put on to stay warm in the extreme cold that's coming," said his mother, Liu Yi.

Cold fronts have been moving across the country this winter, bringing disorder to travel by land, air and sea.

Snow and ice led to the closure of some airports in the Xinjiang Uygur and Inner Mongolia autonomous regions and Shanxi province on Thursday, as well as sections of expressways in Shanxi, the World Civil Aviation Resource Net reported.