Key Facts
• On July 10, 2025, around 8:20 PM, Nagano Prefecture experienced heavy rainfall.
• Approximately 100 mm of rain fell in just one hour near Ikeda Town.
• A “Record-Breaking Short-Term Heavy Rainfall Information” alert was issued.
• The Kanto-Koshin region saw localized rain cloud development during this period.
• Residents are advised to prepare for landslides, flooding, and rising river levels.
• Evacuation to safer locations, such as higher floors, is recommended if necessary.
• “Record-Breaking Short-Term Heavy Rainfall Information” is issued for rare, disaster-level rainfall.
• Evacuation timing is critical: Level 3 for vulnerable groups, Level 4 for all residents.
• Level 5 indicates ongoing disasters, requiring immediate life-saving actions.
• Early evacuation is crucial as severe weather can worsen road and safety conditions.
Summary
Nagano Prefecture experienced record-breaking rainfall on July 10, 2025, with approximately 100 mm falling in one hour near Ikeda Town. This prompted the issuance of a “Record-Breaking Short-Term Heavy Rainfall Information” alert. The Kanto-Koshin region saw localized rain cloud development, raising concerns about landslides, flooding, and river overflows. Residents are urged to evacuate early, especially those in vulnerable areas, and to prioritize safety by moving to higher floors or safer locations. The alert system emphasizes timely evacuation, with Level 3 for vulnerable groups, Level 4 for all residents, and Level 5 indicating ongoing disasters. Early action is critical to avoid life-threatening situations as severe weather can rapidly escalate risks.
