BEIJING - China's meteorological authorities on Saturday issued a blue-coded alert for fog in most parts of the country's central and northern provinces from Saturday night to Sunday morning.

Most parts of north China, southwest China's Sichuan Basin and areas along the Yangtze, Yellow, Huaihe and Han rivers will be covered in light fog during the period, the National Meteorological Center (NMC) warned.

The fog will reduce visibility to less than 1,000 meters in Tianjin Municipality and parts of Hebei, Shanxi, Shandong, Henan, Hubei, Jiangsu, Shaanxi and Sichuan provinces, with visibility as low as 200 meters in some areas, according to the center.

The alert represents the lowest level in China's four-tier color-coded weather warning system.

The NMC has advised residents to protect themselves against possible air pollution. It also told drivers to be aware of road conditions and to slow down to guarantee safety.

The center also forecast light snow in north China and parts of northeast China from Saturday night to daytime on Sunday. South China, along with the Jianghan Plain and areas south of the Yangtze River, can expect to see rainy weather from Monday to Tuesday, it added.