Typhoon Dujuan: September 2026

Typhoon-driven Japan floods impact urban and river catchments

In September 2026, Typhoon Dujuan impacted eastern Japan, bringing intense rainfall to parts of Japan. The event resulted in widespread flood impacts across urban and riverine environments, with significant impacts on the Kanto region around Tokyo, Chiba and Kanagawa Prefectures.

This highlights the vulnerability of densely populated urban areas to prolonged heavy rainfall and typhoon-driven hydrological hazards, drawing renewed attention for effective flood risk management, infrastructure resilience, and preparedness for future extreme weather events. JBA has produced an indicative footprint for the event, based on its stochastic Global Flood Event Set. Download it via our Client Portal or request a copy by emailing eventresponse@jbarisk.com.

We will update the footprint and this report with further information about the event in the coming days.

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