The 12th cyclone of the year, which local media said was the strongest tropical cyclone to reach the populous Yangtze River Delta in the past 10 years, made landfall overnight in Shanghai.
Despite causing flight cancellations at several airports, city metro contingency planning and grinding port activities to halt, there was little damage reported.
However, some photos on China's Twitter-like social media platform Weibo showed shallow-rooted curbside trees uprooted and fallen leaves carpeting roads.
Traveling at a speed of 20-30 km per hour (12-19 miles per hour) in a north-westerly direction, Muifa is now expected to skirt along the eastern coast of Jiangsu province and cross the Shandong peninsula, the China Meteorological Administration said.
Heavy rains will hit northeastern Jiangsu, the central and eastern areas of Shandong, central and eastern areas of Liaoning province, and southeastern Jilin province, forecasters said.
Various areas could see maximum hourly rainfall of 30 to 60 mm (1 to 2 inches), with some localities exceeding 70 mm (3 inches).
Forecasters raised advisory warnings in several provinces for flash flooding at rivers and landslides.