At least six people have died and five more were injured in Japan's Chiba prefecture after rainfall authorities described as "unprecedented" battered the region east of Tokyo on Thursday, August 2025. Chiba Governor Toshihito Kumagai confirmed the deaths in a Friday morning press briefing, saying the prefecture had recorded over 100mm of rainfall per hour since Thursday, August 13, afternoon — roughly three times the normal August average and the highest ever logged in Japanese history.
Record Rainfall and Emergency Response
"This case was an extremely unusual situation, even by Japan's historical weather standards," Kumagai told reporters. "I have responded to many disasters in the past, but I have never experienced a case like this."
The Japan Meteorological Agency said the extreme conditions were caused by warm, humid air from the east colliding with cold air above, creating highly unstable atmospheric conditions. The agency had earlier classified the event as an "unprecedented level of heavy rain."
Local authorities activated a level five emergency warning — their highest alert — on Thursday before downgrading it to level four by Friday morning. Warnings about landslide and flooding risks remain active, with the rain expected to continue through late Friday.
Impact on Residents, Power, and Transport
Power was knocked out to more than 20,000 households, and over 100,000 residents were ordered to evacuate as landslides tore through parts of the prefecture. Around 7,000 travellers were stranded overnight at Tokyo's Narita International Airport, with approximately 1,800 people taking shelter inside the Chiba Prefectural Government building.
Metro passengers were also left waiting at stations as several rail lines remained suspended into Friday morning, and major highways were closed. Among the six confirmed dead was a woman who drowned inside her car on a submerged road. Two others collapsed on the street and later died, according to NHK, Kyodo News Agency, and the Asahi newspaper.
A resident of Ichikawa city in Chiba told NHK the flooding caught her completely off guard. "The power is out so I'm worried whether I can open my business in the next couple of days," she added.
Broader Regional Weather Chaos
The Chiba disaster is part of a broader pattern of extreme weather sweeping across East and Southeast Asia this week. Japan, the Philippines, and China were all struck by three simultaneous typhoons — Dolphin, Chan-Hom, and Peilou — in what forecasters say is shaping up to be an unusually active typhoon season.
Typhoon Dolphin previously brought heavy rain to Japan's Okinawa island, downing trees and cutting power to tens of thousands of buildings. Over the weekend, Chinese authorities evacuated more than one million people ahead of Dolphin making landfall on China's eastern coast, making it the strongest typhoon to hit the country so far this year.
In the Philippines, authorities shut schools and government offices across most of the country's north on Friday, citing the continuing threat of floods. Narita airport said all flights are expected to operate as scheduled on Friday. Japan Airlines noted that some delays are possible but ruled out cancellations.
