Japan is facing heavy rainfall across many areas due to the influence of a monsoon trough, while two strong tropical storms, "Mekkhala" and "Higos," are approaching. Several regions are expected to see accumulated rainfall up to 200 millimeters, with warnings issued for landslides, flooding, and river overflows.
On 26 June 2026 GMT+7, the Japan Meteorological Agency reported that many parts of the country are experiencing heavy rain caused by the seasonal rain trough passing through Japan, combined with warm, moist air masses covering the area, even though the two tropical storms have not yet made landfall.
At 03:30 local time, Kami city in Kochi Prefecture recorded accumulated rainfall of 64.5 millimeters per hour, while Itsuki village in Kumamoto Prefecture measured 46 millimeters per hour. Authorities issued a level 4 warning, indicating that residents should evacuate due to landslide risks in many western and southwestern areas of Japan. Warnings for heavy rain and flooding were also declared in some locations.
Meanwhile, the strong tropical storm "Mekkhala" is moving closer to Okinawa Prefecture, with some areas already feeling its effects. Large rain cloud clusters are expected until before noon on Friday, increasing disaster risk. Additionally, tropical storm "Higos" is forecast to approach Japan's eastern coast on Saturday, drawing moisture into the seasonal rain trough and causing continued heavy rain across many areas.
The Japan Meteorological Agency predicts that by Friday, accumulated rainfall could reach up to 200 millimeters in the Tokai, Kinki, Shikoku, and Okinawa regions. Kyushu and the Amami Islands may see up to 180 millimeters, the Kanto-Koshin region 150 millimeters, and the Chugoku region 120 millimeters.
Japanese authorities have urged the public to remain vigilant against landslides, flooding in low-lying areas, river overflows, as well as dangers from lightning, strong gusty winds, and possible tornadoes in certain locations.