BEIJING - China's national observatory issued a blue alert on Sunday as several southern provinces will be hit by heavy rain Sunday through Monday.

Heavy rain or storms may hit parts of Hunan, Jiangxi, Zhejiang and Fujian provinces, while some areas in Fujian may be hit by hailstones, according to the National Meteorological Center.

The center said temperatures in a number of southern provinces would fall over the next three days, with parts of Guizhou Province likely to experience declines of up to 10 degrees Celsius.

The center warned local authorities and residents in mountainous areas to take precautions against flooding and geological disasters.

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