A tropical storm is brewing off the southern coast of Japan’s southwestern main island of Shikoku and heading northeast, according to the Meteorological Agency.
It is believed to have wind speeds of 66mph and could dump up to a foot of rain in central Japan by Tuesday evening.
Meteorologists say another storm is expected to hit near southern Japan later this week.
The storms could cause flooding in areas already ravaged by the recent typhoon.
Residents in those areas have been warned to prepare early.
Typhoon Hagibis, which was the most powerful typhoon to hit Japan in more than 60 years, left at least 70 people dead and 12 others missing, according to officials.
Japan’s Kyoto News agency put the death toll at 80, citing its own tally.
Some were buried in landslides and others swept away as several rivers overflowed and the Chikuma in Nagano burst its banks.
Tens of thousands of homes were flooded, damaged or without power or running water and many people were forced to stay in evacuation shelters.
The worst-hit areas included Nagano in central Japan, and Fukushima and Miyagi in the north.
On Sunday, Prime Minister Shinzo Abe pledged large efforts to help locate missing people and restore infrastructure.
However at least 13 municipalities in the Miyagi and Fukushima prefectures had to cancel plans for volunteers to join recovery efforts due to fears for their safety.
Many areas are also struggling with large amounts of waste, including flood-soaked furniture and home appliances.
In Nagano, three temporary disaster waste dumps have been opened to deal with the influx of waste.