The mountainous terrain of Taiwan caused Megi to weaken before entering the South China Sea, but the tropical cyclone will likely still be a strong tropical storm or a typhoon at landfall in China.
The Chinese authorities had issued the third highest weather warning in anticipation of the storm.
About 174,000 people from east China's Fujian and Zhejiang provinces have been forced to seek cover and almost 55,000 fishing boats have returned to port to take shelter from the approaching Typhoon Megi.
Schools were closed ahead of the storm, and domestic flights, as well as dozens of worldwide flights, were canceled, according to the Taipei Times.
The typhoon is then expected to continue on its path and hit mainland China.
Four people have been killed and more than 160 were injured after a large typhoon swept across Taiwan.
Authorities estimate that two million households lost power, Hualien, eastern Taiwan, September 27, 2016.
Those areas are still recovering from damage brought by Super Typhoon Meranti earlier this month - the strongest storm for 21 years to hit Taiwan.
Schools were shuttered across the province and train services cancelled, Xinhua reported.
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Taipei was also lashed by downpours and winds, bus services and overground metro trains were suspended as some roads were flooded.
The storm was forecast to move northwest Wednesday and fade gradually.
Yesterday, the island was hit with its third typhoon in two weeks, leaving at least 4 people dead and injuring hundreds more.
"The most active period for typhoons is June through October, with a peak in August and September", said Anna Trevino, senior scientist at AIR Worldwide. It also caused power outages in millions of homes.
The mountainous regions across Taiwan have been affected by torrential rainfall.
Typhoon Megi has caused "widespread transport disruption" in Taiwan and left four million people without a water supply but insured building stock in Taiwan is "typically created to withstand typhoons gusts", Risk Management Systems Inc. said in a report released Tuesday. Over 150 flights at three major airports in Fujian have been canceled.
China shut schools and cancelled dozens of flights as Typhoon Megi made landfall in the southern province of Fujian with winds of close to 120km/h, local media have reported.
Initial report suggests four people have been killed and more than 300 others injured after Typhoon Megi hit Taiwan's northeastern coastline.