BEIJING, July 23 -- China's meteorological authority on Saturday renewed its orange alert for high temperatures in southern and western regions, with temperatures expected to top 40 degrees Celsius in some areas.

A heat wave will sweep across most of areas along the Yangtze, Yellow and Huaihe rivers, regions to the south of the Yangtze River, parts of the northwestern Xinjiang Uygur Autonomous Region, and the southwestern Sichuan Basin, on Saturday, the National Meteorological Center (NMC) said.

The central and eastern parts of regions to the south of the Yangtze River, areas along the Yangtze and Huaihe rivers and Chongqing municipality in the southwest would probably see temperatures above 40 degrees Celsius, said the center.

The NMC warned local people in the affected areas to take precautions.

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