BEIJING, May 21 (Xinhua) -- China's national weather observatory renewed a blue alert for rainstorms on Monday evening, as heavy rain in western, southern and eastern areas will continue till Tuesday evening.

Heavy rain or storms may hit parts of Chongqing, Guizhou, Hubei, Hunan, Jiangxi, Sichuan and Zhejiang, with some of these areas seeing thunderstorms and hailstones, according to the National Meteorological Center (NMC).

Rainfall could exceed 100 millimeters per hour in some regions of Chongqing, Hubei and Sichuan, the NMC said.

The NMC warned local authorities to reduce outdoor activities and take precautions against flooding, flash floods and landslides.

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