Typhoon Choi-wan was on course Sunday to pass south of Japan on its way out into the Pacific Ocean, the Meteorological Agency said.
As of 9 p.m., the typhoon was located about 120 km southwest of Hachijo Island, moving northeast at a speed of 35 kph, the agency said.
The season's 15th typhoon had an atmospheric pressure of 965 hectopascals at its center and was packing winds of up to 126 kph.
The agency said the possibility the typhoon could hit land on the archipelago diminished, but it also warned it may come closest to the Kanto area by Monday noon, bringing with it heavy rainfall.
By 9 a.m. Monday, it was expected to come within a 130-km radius from a point 200 km southeast of Choshi, Chiba Prefecture, the agency said.
In the 24 hours to 6 p.m. Monday, the typhoon was expected to bring some 200 mm of rain to the southern part of the Izu Islands and some 150 mm to the Kanto area, the agency said.
It was expected to bring 100 mm of rain to the Tokai region.