A man in his 70s, surnamed Wang, takes a cold shower after a wintry swim in Shichahai Lake in Beijing on Sunday. Wei Xiaohao / China Daily

Key expressways were closed and flights were canceled over safety concerns on Sunday, as a wide area of northern China was hit by a snowstorm that disrupted transportation.

At the same time, the National Meteorological Center renewed a blue alert, the lowest level in a four-tier warning system, for snowstorms in the north of the country.

Snowstorms were expected to hit Inner Mongolia autonomous region and northern provinces of Shanxi and Hebei as well as Beijing and Tianjin municipalities on Monday, with some areas likely to see snowfall of 12 millimeters.

Schools in mountainous areas in Beijing were due to be closed on Monday due to lasting snowfall, according to local education authorities.

Traffic management authorities and police patrolled highways ready to rescue potential victims of traffic accidents. Six expressways that connect Beijing to other parts of China were temporarily closed to prevent traffic accidents due to the heavy snow, said the Beijing Traffic Management Bureau. In Tianjin, all highways were shut down until the snow stopped falling.

On Thursday, the center had issued a warning on the coming blizzard and reminded residents in northern China of the sharp decline in temperature and possible traffic difficulties. On Saturday, the traffic was less than the previous weekend as many people heeded the warnings and stayed home.

"Such a heavy snowfall has not occurred often before, and the pre-warning helped to alert people of possible dangers," said Sun Jun, chief forecaster at the center.

Before the snow, the Beijing Municipal Commission of Transport organized a team of 4,100 rescuers to deal with potential accidents. The commission also prepared 1,500 machines and 24,000 metric tons of deicing liquid and salt to melt the snow.

Airports canceled flights, as the airplanes would not be able to take off and land safely on slippery runways. The Beijing Capital International Airport alone canceled about 150 flights by Sunday afternoon, according to the airport's statement. More than 20 flights were delayed at Tianjin Binhai International Airport.

Thousands of visitors swarmed into the Forbidden City to experience the old palace covered in snow.

huyongqi@chinadaily.com.cn