The storm is moving towards the island of Okinawa, heading from the southeast at 20 kilometres per hour and destined for land by Tuesday morning, weather experts say.
Winds gusting in the typhoon's vortex reach 70 metres per second, which can flip a car and whip coastal waves 14 metres high. The government has set up an emergency centre. Okinawa residents have been told not to approach the coastline.
Heavy rain is triggering floods and landslides north of Okinawa on the island of Kyushu, where 87,000 people have been told to evacuate. Record precipitation of 370 millimetres was reported around the city of Amakusa over the past day.
More large-scale natural disasters are not ruled out.