Japanese weather officials are urging residents of Hachijo Island in Tokyo’s Izu Islands to be on high alert for mudslides.
Heavy rain is also expected along the Pacific coast from western to northeastern Japan.
Residents are advised to check the latest weather and traffic information, evacuate early from places at risk of disaster, and stay away from dangerous places such as flooded roads.
The Japan Meteorological Agency said a series of rain clouds developed over the Izu Islands.
Hachijo Island recorded 291 millimeters of rainfall during the 12-hour period through 11 a.m. on Sunday, reaching nearly 80 percent of the average rainfall for the entire month of September.
People on the Izu Islands are advised to be on high alert as bands of heavy rain clouds could form through dawn on Monday.
The agency also announced that bands of heavy rain clouds could develop in the southern Kanto and Tokai regions from Sunday night through Monday, dramatically raising the risk of a heavy rain disaster.
The autumn rain front and the Tropical Storm Krovanh are expected to bring heavy rain to a wide range of regions along the Pacific coast from western to northeastern Japan. The agency said people should be on the alert for heavy rain through Thursday.
Heavy rain could have a major impact during the hours when people are returning home on Sunday and commuting to work or school on Monday morning.