The remnants of Typhoon Haikui drenched southern China for a third day since making landfall, and airports in Guangdong province cancelled hundreds of flights due to stormy weather on Thursday though winds had weakened.

Although storm clouds moved westward towards Guangdong, one of the country's richest provinces, more downpours were still forecast for the southeastern province of Fujian, where state media reported economic losses had reached 5.054 billion yuan ($690.81 million) since the typhoon made landfall on Tuesday.

In Guangdong's capital Guangzhou, Baiyun Airport, one of the busiest in China, cancelled 316 flights and delayed 271, according to flight tracking app Flight Master. Shenzhen's Baoan Airport cancelled 176 flights and delayed half of its flights while Zhuhai's Jinwan Airport cancelled 91 and delayed 74.

Torrential rain reportedly led to rivers overflowing in the Guangdong town Tangxi, and some villages suffered severe waterlogging. Over 350 people, including elderly, women and children were relocated from low-lying areas, according to state media.

The China Meteorological Administration forecast rainstorms in central and eastern Guangdong, the southern part of Jiangxi province, southern areas in Hunan province, the northeastern areas of the Guangxi region, and the central part of the island of Hainan, while northern parts of Guangdong and the southeastern coast of the province were expected to be hit harder.

Later this week, the storms are expected to continue in Guangxi bringing the southwestern region extreme rainfall on Friday and Saturday before potentially dissipating on Sunday. Authorities issued warnings of mountain torrents and geological disasters for the cities of Guilin, Laibin, Guigang and Wuzhou.

Flooding in parts of Fujian province during the past two days forced the evacuation of nearly 300,000 people and damaged more than 2,500 homes.

Almost 10,000 hectares (24, 710 acres) of crops in Fujian were inundated.

Intense rains in the city of Fuzhou shattered 12-year-old rainfall records, surpassing the amount brought by Typhoon Doksuri late July.

($1 = 7.3160 yuan) (Reporting by Liz Lee and Shanghai newsroom; Additional reporting by Sophie Yu; Editing by Christian Schmollinger & Simon Cameron-Moore)