Record rainfall causes deadly flooding near Tokyo, killing at least 8 and forcing mass evacuations

Aug 14, 2026

Record-breaking rainfall in Japan's Chiba prefecture triggers severe flooding east of Tokyo, killing at least eight people and prompting evacuation advisories for nearly 230,000 residents. The deluge, which exceeds 360mm in 24 hours, strands 7,000 travelers at Narita International Airport and knocks out power to 68,000 homes. The Japanese Ground Self-Defense Force deploys to rescue thousands stranded at Soga station, while experts attribute the severe urban flooding to paved surfaces overwhelming local sewer capacities.

Record Chiba rainfall levels

▪The Japan Meteorological Agency downgraded its most severe heavy-rain warning in more than a dozen Chiba municipalities on August 14, 2026, while forecasting more rain.
▪Parts of Chiba prefecture recorded over 360mm of rain in 24 hours, including hourly rates of 1.5 centimeters in Chiba City and 9.7 centimeters in Sakura.
▪Nearly 230,000 residents in Chiba prefecture were advised to evacuate due to severe flooding on August 14, 2026.
▪Record-breaking rainfall on August 13, 2026, flooded cities east of Tokyo in Chiba prefecture, prompting the Japan Meteorological Agency to issue its highest heavy rainfall warning.

Flood deaths in vehicles

▪Chiba prefecture officials confirmed that flood-related deaths included a man found floating in Ichikawa, a woman stuck in a flooded car in Sakura, and two people pulled from flooded cars in Kashiwa and Chiba.
▪Severe flooding in Chiba prefecture killed at least eight people and injured over 30 others as of August 14, 2026, according to emergency and media reports.

Narita airport travelers stranded

▪Flights in and out of Narita International Airport operated normally on August 14, 2026, as many travelers were returning home at the end of Japan's Bon Buddhist holiday week.
▪Severe flooding disrupted transport networks and stranded thousands of travelers, including around 7,000 overnight at Narita International Airport, before train services partially resumed on August 14, 2026.

Power outages across region

▪Floodwaters inundated at least 170 homes in Chiba prefecture and caused a landslide that blocked a road in the city of Togane as of August 14, 2026.
▪Torrential rain and flooding caused widespread power outages across Chiba prefecture, affecting 68,000 homes on August 13, 2026, before TEPCO Power Grid restored power to all but 18,000 homes by August 14, 2026.

Military evacuation operations

▪The Japanese Ground Self-Defense Force deployed military personnel and dispatched buses to evacuate approximately 4,000 stranded people who stayed overnight at Soga train station.
▪Hundreds of displaced residents sought shelter overnight at the Chiba prefectural government building and public facilities following the unprecedented weather event.

Urban sewer capacity exceeded

▪University of Tokyo civil engineering professor Koji Ikeuchi stated that the torrential rainfall likely exceeded the designed sewer capacity of Chiba's urban areas.
▪Professor Koji Ikeuchi told the Nikkei business daily that extensive asphalt and concrete coverage in Chiba's urban areas prevented rainwater absorption, exacerbating the overflow.