Key Facts
• August 20: Heavy rain hit Semboku City, Akita, due to unstable atmospheric conditions.
• 260 mm of rainfall recorded in 24 hours, the highest in August’s observation history.
• Hinokinai River overflowed, isolating 20 households (46 residents) in Nishiki Town.
• Roads were flooded or blocked by debris, hampering access to affected areas.
• Emergency responders delivered food and supplies on foot; no injuries reported.
• A resident described water rising to knee level rapidly, forcing evacuation to the second floor.
• Forecast: Up to 180 mm of rain in northern Tohoku and 100 mm in southern Tohoku by August 21 evening.
Summary
Semboku City in Akita Prefecture experienced record-breaking rainfall on August 20, with 260 mm recorded in 24 hours. The heavy rain caused the Hinokinai River to overflow, isolating 20 households and 46 residents in Nishiki Town. Flooded and debris-covered roads hindered rescue efforts, but emergency responders delivered supplies on foot. Despite significant property damage, no injuries were reported. Residents described the rapid rise of water levels, forcing them to seek higher ground. The Japan Meteorological Agency forecasts continued rainfall, with up to 180 mm expected in northern Tohoku and 100 mm in southern Tohoku by August 21 evening.
