The government in the key port city of Kaohsiung, right on the path of the eye of the storm, told people on Wednesday to stay at home and away from the sea, rivers and mountains, warning of a repeat of 1977's Typhoon Thelma which killed 37 people and devastated the city of 2.7 million.
Taiwan regularly gets hit by typhoons but they generally land along the mountainous and sparsely populated east coast facing the Pacific, but Krathon will make landfall on the island's flat western plain.
Taiwanese residents are preparing for the arrival of Typhoon Krathon. (AP PHOTO)
It is forecast to hit between Kaohsiung and its neighbouring city of Tainan in the early hours of Thursday, then work its way up the west coast towards the capital Taipei, the Central Weather Administration (CWA) said.
All cities and counties in Taiwan declared a day off on Wednesday, shutting financial markets. Domestic flights have been cancelled for the day, along with 246 international ones.
The north-south high speed rail line remained open, but with a reduced number of operations.
The typhoon has weakened, but the threat from a storm surge and strong winds and rain remains as it slowly makes its way towards Taiwan's coast, the weather administration said.
"Because of Typhoon Gaemi being quite severe earlier this year, everyone is more cautious and prepared this time around," said sales representative Yu Ren-yu, 35, picking up sandbags at a government office, referring to July's storm that killed 11.
"First be prepared, then we can face this typhoon."
Chou Yi-tang, a government official working in the Siaogang district where the airport is located, said the typhoon has brought back bad memories of Thelma for the older generation, prompting residents to take extra precautions.
"We were hit directly by the eyewall," he added, of the events almost five decades ago. "Power was out for two weeks and no water for almost a month. It was disastrous."
In his district, more than 700 sandbags have been distributed, which is a record for a typhoon, while authorities are making more to meet demand, Chou said.
Taiwan's defence ministry said it had put more than 38,000 troops on standby.
The fire department reported 46 injuries, mostly in the mountainous eastern county of Taitung, with one person missing in central Taiwan's Yunlin county.
TSMC, the world's largest contract chipmaker and a major Apple and Nvidia supplier, said on Tuesday it does not expect a significant impact to its operations from the typhoon.
TSMC's factories are along Taiwan's west coast, including in the city of Tainan.Â
