BEIJING, Feb 18 -- Snowstorms have been sweeping parts of China, wreaking havoc on traffic and crops.

Statistics from the meteorological station of central China's Hunan Province showed that 37 cities and counties were covered by snow on Tuesday morning.

The snow coverage on Hengshan Mountain and in Huaihua City was as thick as 16 and eight centimeters respectively, and seven cities including the provincial capital of Changsha will see snowfall of more than 7.5 millimeters by Wednesday, according to the station.

It also warned that the extreme weather will damage crops and that farmers should use more fertilizer that can improve their plantations' resistance to cold.

According to Guangzhou Railway Group, due to the heavy snow in the provinces of Hunan and Hubei, train drivers have been told to limit their speed to 160 km per hour on a section of the Beijing-Guangzhou high-speed line between Chibi City in Hubei and Changsha City in Hunan.

In southwest China's Guizhou Province, the snow led to temporary closure of the airport in the provincial capital of Guiyang.Guiyang Longdongbao International Airport was closed at 8 a.m. for snow and ice removal.

More than 90 flights were canceled and over 9,000 passengers were affected before the airport was reopened at noon.

Guizhou transport authorities said heavy snow and rain meant traffic controls have been necessary on six expressways and many roads in the province.

The provincial meteorological station forecast that several cities including Guiyang will see snowfall of over six millimeters on Tuesday.

Snowstorms also delayed more than 30 flights at Nanjing Lukou International Airport in east China's Jiangsu Province on Tuesday morning, according to the airport authorities.

Transportation along the Yangtze River has likewise been hit.

The maritime bureau of Anqing City in east China's Anhui Province issued a warning on Tuesday morning indicating that the Anqing section of the Yangtze River will see more than four millimeters of snow within 12 hours.

The maritime authority of Anqing port have sent snowstorm warnings to ferries and ships, and they have also strengthened supervision over transportation.

China's National Meteorological Center continued to issue a blue alert for snowstorms on Tuesday morning, warning that blizzards will hit parts of Hubei, Jiangxi, Anhui and Zhejiang.

The center said heavy snow will also sweep parts of Hunan, Yunnan and Guizhou from Tuesday morning to Wednesday morning.

The country's weather observatory forecast that the bad weather will ease from Wednesday.

China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.