Record rain in Japan's Chiba prefecture kills four, strands thousands at Narita airport

Record rainfall strikes Chiba

More than 360 millimetres of rain fell in 24 hours in parts of Chiba prefecture, which borders Tokyo to the east and is home to approximately 6 million people, as torrential downpours hit the region on Thursday evening, 13 August. The Japan Meteorological Agency (JMA) issued its highest-level heavy rain warning (level 5) for Chiba for the first time, with an official telling a Thursday evening news conference that the region was "shaping up to be an unprecedented level of heavy rain." The warnings were downgraded to level 4 by Friday morning. The storm struck during one of Japan's busiest holiday weeks, compounding the disruption to travel and transport networks.

Casualties and damage

The Chiba Prefecture Disaster Management Office confirmed four deaths by Friday morning. The victims included a 66-year-old woman found in her submerged car on a flooded road, a man in his 60s or 70s found floating on a flooded road, a man of unknown age found collapsed in the street who died after being transported to hospital, and a fourth person whose age and gender had not been determined. A fifth person was found unconscious and feared dead, and a sixth remained unaccounted for. Soldiers were deployed to the area to assist with relief efforts.

Close to 26,000 households across Chiba were without power on Friday morning, according to the disaster management office, while Reuters and Deutsche Welle reported nearly 25,000. A total of 45 houses were flooded in cities including Ichikawa, Kashiwa and Sakura, with another 39 homes seeing water seep in below the floorboards. According to Kyodo news agency, cited by NOS, 126,000 people were ordered to evacuate, with more than 200 evacuation centres opened across the prefecture.

Thousands stranded at Narita

Between 6,000 and 7,000 travellers were stranded overnight at Narita airport, one of Tokyo's two main international airports, after train services to and from the airport were cancelled into Friday afternoon. Airport staff distributed water, food and sleeping bags to those stuck in the terminal, according to posts on social media by affected passengers. All flights were scheduled to operate normally on Friday, an airport spokesperson said, though Japan Airlines indicated some flights could experience delays. Hundreds more people were stranded at Chiba railway station after train services were suspended, and hundreds spent the night in shelters. NHK footage showed cars submerged up to their headlights in Kashiwa city.

Official response and ongoing disruption

Chiba Governor Toshihito Kumagai told reporters on Friday morning that the situation was extraordinary.

This case was an extremely unusual situation, even by Japan's historical weather standards. I have responded to many disasters in the past, but I have never experienced a case like this.

Key highways in Chiba, including routes connecting Narita airport to central Tokyo, remained closed on Friday, according to highway operator NEXCO East, forcing drivers onto alternative routes and causing heavy traffic. Some train services connecting Narita to Tokyo had resumed operations by Friday morning, though several rail services remained suspended. A woman in Ichikawa city told NHK that the flooding caught residents off guard, saying the power outage left her worried about whether she could open her business in the coming days. A stranded traveller at Narita told the same broadcaster he "never thought I'd spend the night at the airport" and that "we're never going to forget this trip."