At least six people were dead and eight others missing after Typhoon Nepartak battered China's coastal Fujian Province with heavy rain and strong winds that destroyed homes and triggered landslides.
Fujian's water resources department said more than 438,000 people had been relocated.
Hundreds of flights and trains were cancelled, while damaged power stations left swaths of the province without electricity.
Nepartak, the first typhoon of the season, first struck Taiwan on Friday with even greater power, leaving two people dead and 72 injured.
It weakened into a strong tropical storm after making landfall in Fujian on Saturday, but continued to soak the region, where emergency workers scrambled to reach residents trapped on the upper floors of submerged buildings and collapsed homes.
The storm moved on Sunday into neighbouring Jiangxi Province, where 500 people have been evacuated, the Chinese civil affairs ministry said.
Unusually heavy rain has pounded southern China in recent months, triggering severe flooding along rivers, including the Yangtze.
Meteorologists blame the floods on a particularly intense El Nino weather pattern that has resulted in up to a 50% increase in rainfall in certain areas.
The government said on Friday that 164 people have been killed by floods, hail and landslides since June 30, while 32 million people across 26 provinces have been affected.
Dramatic pictures have emerged of people pushing cars through waist-high water and a football stadium with rainwater filled to its upper rafters in Wuhan, a central Chinese city that has been particularly hard hit.