Southern China has been hit by the heaviest rainfall since the start of the flood season in mid-May, with 121 national meteorological monitoring stations breaking monthly precipitation records, according to the National Meteorological Center.

Meanwhile, another round of heavy rain is expected to affect central and eastern China until May 29, which is likely to hit the main region in Hubei province, the central parts of Jiangsu and Anhui provinces, northern parts of South China and western parts of Southwest China, the center said.

Most of these areas are likely to see cumulative rainfall of 100 to 150 millimeters, with some places exceeding 250 mm.

Chen Boyu, chief forecaster at the center, attributed the prolonged heavy rains to a stable moisture transport belt from the Indian Ocean via the Indochina Peninsula to Hainan province, the Guangxi Zhuang autonomous region and Guangdong province.

It was also related to stronger-than-usual subtropical highs, as well as abnormal geopotential heights over eastern China's coastal waters that enhanced moisture transport and slowed the westerlies, causing rain belts to move slowly and resulting in persistent downpours, Chen said.

Between May 15 and 21, the regional heavy rain process featured large cumulative precipitation, long duration and high intensity. From 6 am Wednesday to 6 am Thursday, 52 national meteorological monitoring stations recorded extremely heavy precipitation, 442 stations recorded heavy rain and two stations broke historical precipitation records.

The heaviest rainfall was mainly in Guangdong and Guangxi. The largest cumulative rainfall was almost 673 mm in Enping, Guangdong, and the maximum hourly rainfall was 124.9 mm in Huidong county, Guangdong. A total of 121 national meteorological monitoring stations broke monthly precipitation records during this period, while five stations broke historical precipitation records.

Guangdong has activated a Level IV emergency response for disaster relief as torrential rains and flooding swept the province beginning on Thursday, with more than 23,000 residents evacuated and no casualties reported as of Friday.

In a statement released on Friday, the Guangdong Provincial Disaster Reduction Commission said that prefecture-level cities and relevant provincial departments had been instructed to prioritize emergency relief operations to ensure that affected residents were safely resettled.

Guangdong entered its annual "dragon boat rain" season — the colloquial name for the province's early summer monthlong rainy period — on Thursday, water conservancy authorities said.

The most severe flooding has centered on the Moyangjiang River in Yangjiang, southwestern Guangdong. At 11 pm Thursday, the Guangdong Hydrological Bureau issued an orange flood warning — the second most severe in the country's four-tier system — for the Jiangcheng section of the river. By Friday morning, the station had recorded a flood peak discharge of approximately 4,000 cubic meters per second, with the peak water level hitting around seven meters.

On Thursday evening, the office of the State Flood Control and Drought Relief Headquarters held an emergency consultation with three other ministries to assess the ongoing rainfall in central and eastern China, and to coordinate flood prevention efforts.

The authorities emphasized the importance of a people-first approach, stepped-up monitoring and early warnings, and highlighted that key locations such as embankments, reservoirs and crowded places should be inspected. They added that rescue teams, supplies and backup communication equipment should be pre-positioned.

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