BEIJING, Jan. 25 -- China's meteorological authority renewed a yellow alert for a cold wave on Saturday, as most parts of the country will see temperatures plunge by 8-12 degrees Celsius over the next three days.

During the period, some areas in the eastern part of northwest China, as well as western sections of north China and Sichuan plateau are expected to experience declines of over 14 degrees Celsius, said the National Meteorological Center (NMC).

The NMC has advised the public to keep warm, and called for necessary measures to protect crops and aquatic products.

The center also renewed a yellow alert for heavy fog, warning that visibility in some areas including the Qiongzhou Strait, the coastal waters of the Leizhou Peninsula and Guangxi will be reduced to less than 1 kilometer, and in some instances, even below 500 meters from Saturday morning to evening.

Drivers have been asked to maintain safe speeds, while airports, freeways and ports have been instructed to take appropriate safety measures.

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