Record-breaking short-term heavy rain has triggered Level 4 landslide danger warnings for the towns of Rikubetsu and Shihoro in Hokkaido [1, 2].
The emergency alerts follow an intense weather system that has put residents at immediate risk of landslides and flooding. Local authorities are monitoring the situation as the region faces a period of extreme instability due to saturated soil.
Observations near Rikubetsu town recorded hourly precipitation of approximately 90mm [1]. Reports from other areas indicate similar intensity, with precipitation near Kamishihoro town reaching approximately 90mm, and levels near Shihoro town peaking at approximately 100mm [2]. These figures represent record-level rainfall for the short-term window in these specific locations.
Meteorologists said the extreme weather was caused by the inflow of warm, moist air into northern Japan, which created localized areas of intense precipitation [1]. The Level 4 warning is the highest tier of urgency, signaling that residents should take immediate action to evacuate or move to safer ground [1].
The threat of heavy rain is expected to expand beyond Hokkaido. Forecasts indicate that heavy rainfall will continue across the Tohoku region, particularly on the Japan Sea side, through Monday, July 13 [1, 2, 3]. Expected 24-hour precipitation for the Tohoku Japan Sea coast is approximately 120mm [1].
Regional officials are urging citizens to remain vigilant and follow evacuation orders as the weather system moves across northern Japan. The combination of record hourly rainfall and prolonged precipitation increases the likelihood of slope failures and flash flooding in mountainous terrain [1, 3].
“Record-breaking short-term heavy rain has triggered Level 4 landslide danger warnings.”
The issuance of Level 4 warnings in Hokkaido, combined with the projected 120mm of rain in Tohoku, suggests a high-risk weather pattern across northern Japan. Because the rainfall is concentrated in short bursts—reaching up to 100mm per hour—the ground cannot absorb water quickly enough, significantly increasing the risk of sudden landslides and debris flows even in areas not typically prone to such events.
