Torrential rains from two tropical storms triggered severe flooding and landslides across western Japan in late June 2024.
The extreme weather disrupted critical transport infrastructure and forced massive population shifts during a major holiday week. Because the Kyushu region is prone to mudslides, the sudden intensity of the rainfall created an immediate threat to life and property.
Authorities issued evacuation orders for approximately one million people [1] as the risk of landslides remained high. While some reports indicated calls for millions of residents to move, other officials specified the figure at about one million [1]. A Japan Meteorological Agency spokesperson said the government ordered these evacuations due to the persistent risk of slope failure.
The storms, identified as Mekkhala and Higos, produced intense downpours that overwhelmed rivers and mountainsides. In Kumamoto prefecture and other parts of the southern island of Kyushu, the rainfall led to mudslides and flooding that injured several residents [3]. An Associated Press reporter said the weather halted travel during the Buddhist holiday week [3].
Transport disruptions extended to the skies, with more than 200 flights canceled across Japan [2]. Local governments and the Japan Meteorological Agency remained on high alert as the storms moved through the region.
An NHK World Japan weather reporter said, "We are calling on people to stay alert for further landslides, overflowing rivers, lightning and strong winds."
Emergency crews worked to manage the aftermath of the Monday rains, which had already caused significant flooding and mudslides across the region [3]. The combination of two approaching tropical systems intensified the precipitation, leaving several areas of southwestern Japan struggling to drain excess water.
“The government has ordered the evacuation of about one million people as the risk of landslides remains high.”
The convergence of two tropical storms—Mekkhala and Higos—demonstrates the vulnerability of Japan's southwestern topography to rapid-onset flooding. The scale of the evacuation orders and the disruption of travel during a holiday period highlight the significant logistical challenges the Japanese government faces when managing climate-driven disasters in high-risk zones like Kyushu.
