Most shops and schools were shut across Taiwan on Friday as Typhoon Champi neared the island, forcing hundreds of people to leave their homes ahead of the powerful storm.
The typhoon is expected to sweep past Taiwan's northeast as it moves towards China and Japan, triggering the cancellation of hundreds of flights in the region.
At least one person has been killed in Taiwan after being swept away by waves whipped up by the typhoon, authorities said. Dozens of others have been injured.
Champi is the latest in a busy Pacific storm season turbo-charged by the El Nino weather phenomenon that has caused unprecedented warming in the equatorial Pacific.
The storm was briefly a super typhoon as it crossed the ocean, but has since weakened and is now packing maximum sustained wind speeds of 176 kilometres (109 miles) per hour, according to the latest update from the Joint Typhoon Warning Center.
Heavy rain, strong winds and giant waves are forecast for Friday and Saturday, and thousands of military personnel are on standby to assist with rescue efforts.
More than 1,200 people had been evacuated from their homes ahead of Champi.
"As it approaches Taiwan's northeastern tip... the typhoon may slow down. If it slows down, its impact will last longer," Central Weather Administration administrator Lu Kuo-chen told a briefing.
Extremely heavy rain
Champi is expected to dump up to 90 centimetres (35 inches) of rain from Thursday to Saturday, with northeastern Taiwan to be hardest hit, the forecaster said.
"People should be aware that the strong winds and extremely heavy rain will continue into the first half of tomorrow," Lu added.
Work and classes were cancelled for the day across nearly all of Taiwan, leaving streets quiet as most locals hunkered down at home to wait out the storm.
Some businesses installed sandbags or metal barriers at entrances to prevent flooding of their premises.
"I'm worried about flooding. The vegetables could get flooded and rot, a 73-year-old farmer surnamed Tsai told AFP in New Taipei City.
Convenience store worker Peter Chen said he was concerned about the weather conditions on Friday night when the eye of the typhoon would be closer to Taiwan's coast.
"We might prepare some sandbags," the 27-year-old said.
The United Nations said Wednesday that the El Nino system gripping the planet is heading off the charts, and that countries should take urgent action to prepare for the worst.
El Nino is expected to peak in December, but the human impact is set to last into 2027 and beyond.
The warming phase of a natural climate cycle, El Nino temporarily raises sea temperatures in the tropical Pacific, triggering changes in weather that can increase the risk of drought and flooding, and exacerbate human-caused global warming.