21 killed, 4 missing as heavy rain hits Central China

The downpours will push the maximum temperature below 30 C in areas along the Yangtze River, lower than normal at this time of the year.

The center said the constant rain along the Yangtze River is the result of cold air from Northeast China moving southward and meeting warm, wet air from South China.

On Monday, Harbin, the capital of Northeast China's Heilongjiang province, saw its daily average temperature drop to 19.8 C, likely marking the start of autumn, the center said.

Heat will linger for the next few days in South China, with temperatures rising to 35 C. Hot, humid weather has scorched Haikou, the capital of Hainan province, for 48 days, more than the annual average of 27, the center said.

Luo Wangshu and Xinhua contributed to this story.