Muifa is the strongest tropical cyclone to hit the multimillion-dollar city of Shanghai since records began in 1949, state CCTV reports.
However, there are no reports of anyone being injured.
At least 426,000 people were evacuated in Shanghai and another 1.2 million people were taken to temporary shelters in the coastal province of Zhejiang.
All passenger flights at Shanghai’s two international airports were halted on Wednesday. Air traffic from Shanghai has slowly started to resume.