The bottom of a residential building is flooded in downtown Shunchang county, Nanping city, Fujian province, July 3, 2015.[Photo/Xinhua]

BEIJING -?China's meteorological authority on Sunday continued to issue a blue alert, the lowest in a four-tier warning system, as rainstorms will hit most parts of the country's southern regions.

Parts of Hunan, Jiangxi, Zhejiang provinces and Guangxi Zhuang autonomous region will see torrential rains, strong winds or hail on Sunday, the National Meteorological Center (NMC) said in a statement on its website.

The rainfall is expected to reach 50 to 90 millimeters in the provinces of Zhejiang, Jiangxi, Hunan and Fujian, according to the statement.

The NMC suggested people affected by the rainstorms take precautions against possible mountain torrents, mud-rock flows and landslides and avoid outdoor activities.

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