Six Dead as Unprecedented Rainfall Hits Japan, Flooding Chiba and Leaving Thousands Stranded Near Tokyo

At least six people have died and five others have been injured after record-breaking rainfall caused widespread flooding and landslides in Japan’s Chiba prefecture, just east of Tokyo. Authorities described the rainfall as unprecedented, with more than 100mm falling in a single hour and thousands of people stranded as roads, rail services and flights were disrupted.

The Japan Meteorological Agency said the extreme conditions were caused by warm, humid air flowing into eastern Japan and meeting colder air higher in the atmosphere, creating an unusually unstable weather system. Chiba recorded more than 100mm of rain per hour from Thursday afternoon — around three times the region’s average August rainfall and the highest volume of precipitation ever recorded in Japan.

Authorities issued their highest-level emergency warning on Thursday as flooding and landslide risks increased. More than 100,000 households were urged to evacuate, while the alert was later downgraded to level four on Friday morning. Officials continued to warn residents to remain cautious as heavy rain was expected to continue.

The rainfall has already caused significant damage and disruption. More than 20,000 households lost power, while several railway services and major highways remained closed. Images from Oamishirasato showed cars abandoned on flooded streets as rising water made roads dangerous or impossible to use.

Among those who died was a woman who was trapped inside a car submerged on a flooded road. Two other people reportedly collapsed in the streets and later died. Rescue teams continued searching affected areas as authorities assessed the extent of the disaster.

Transportation was also badly affected. Around 7,000 travellers were reportedly stranded overnight at Narita International Airport, while passengers were also left waiting at railway stations. About 1,800 people spent the night at the Chiba Prefectural Government building after being unable to travel home.

Narita Airport said flights were expected to operate normally on Friday, although Japan Airlines warned that some services could still face delays.

Chiba Governor Toshihito Kumagai said the situation was unlike anything he had experienced during his years responding to disasters, describing the rainfall as an extremely unusual event even by Japan’s weather standards.

The severe weather comes as several parts of East Asia experience a succession of powerful storms. Japan, China and the Philippines have all been affected by heavy rainfall and tropical weather in recent days. Typhoon Dolphin, which also affected Japan’s Okinawa island, later struck eastern China, prompting the evacuation of more than a million people.

In the Philippines, authorities have also continued closing schools and government offices in parts of the north because of flooding risks.

For Chiba, the immediate concern remains the possibility of further flooding and landslides as saturated ground struggles to absorb additional rainfall. Emergency teams have been instructed to prioritise rescue operations, while residents have been urged to follow evacuation orders and avoid flooded roads.