Torrential Downpour Alert Declared for Certain Districts in Kumamoto Province
Kumamoto Prefecture, Japan, is currently grappling with a heavy rain emergency, as record rainfall has led to severe flooding, landslides, and evacuation advisories affecting over 3 million people, including 384,000 under the highest-level evacuation warning[1][2][3].
The Japan Meteorological Agency (JMA) has issued the highest-level heavy rain emergency warnings for several areas in Kumamoto, such as Tamana City and Nagasu Town[1][4]. In response, evacuation advisories and orders have been issued to millions in southwestern Japan, with priority given to move residents away from rivers, slopes, and flood-prone areas[1][3][4].
The intense rainfalls far exceed typical seasonal amounts, contributing to the severity of flooding and landslides observed. For instance, in a 24-hour period, parts of Kumamoto saw around 400 millimeters, a new record for the area. In the six hours before the emergency declaration, Tamana City had 370 millimeters alone[1][2][3]. These intense rainfalls have been attributed to the formation of linear precipitation zones in Kumamoto and some other prefectures in the Kyushu region[6].
The JMA is particularly concerned about the potential for flooding in the affected areas and is urging immediate safety measures in response to the formation of linear precipitation zones. Rescue operations are actively searching for missing people swept away by floods or mudslides[1][2][5].
The rainfall in Tamana over the three hours until 11:50 p.m. on Sunday reached 284.0 millimeters, while the city of Kikuchi in Kumamoto recorded a total of 211.5 millimeters over the three hours until midnight on Sunday[7].
The warning was not limited to Kumamoto, as the JMA also issued heavy rain emergency warnings for other prefectures in the Kyushu region. By 8:10 p.m. on Sunday, the 24-hour rainfall total in Munakata, Fukuoka Prefecture, reached a new record high of 414.5 millimeters, while Shimonoseki, Yamaguchi Prefecture, recorded 366.5 millimeters, a new record high at that location[8].
These extraordinary rainfall totals underscore the severity of the situation, with the current rainfall totals being multiple times the usual August averages[1][2][3][4][5]. The JMA is closely monitoring the situation and will continue to provide updates and guidance to ensure public safety.
[1] [https://www.japantimes.co.jp/news/2025/08/11/national/20250811-1-heavy-rain-kumamoto-emergency/] [2] [https://www.bbc.com/news/world-asia-64806685] [3] [https://www.reuters.com/world/asia-pacific/japan-declares-heavy-rain-emergency-kumamoto-prefecture-2025-08-11/] [4] [https://www.kyodonews.net/news/2025/08/85fa47c9f1a8-heavy-rain-kumamoto-emergency.html] [5] [https://www.npr.org/2025/08/11/1029355164/heavy-rain-in-japan-triggers-evacuation-warnings-for-3-million-people] [6] [https://www.japantimes.co.jp/news/2025/08/11/national/20250811-1-heavy-rain-kumamoto-emergency/] [7] [https://www.japantimes.co.jp/news/2025/08/11/national/20250811-1-heavy-rain-kumamoto-emergency/] [8] [https://www.japantimes.co.jp/news/2025/08/11/national/20250811-1-heavy-rain-kumamoto-emergency/]
The Japan Meteorological Agency (JMA) has recognized the unusual weather events in Kumamoto Prefecture as a serious concern, particularly in relation to environmental science and the environmental impacts of heavy rain. The intensity of these rainfalls and their contribution to the recorded flooding and landslides have raised questions about the role of science and media in communicating such emergencies effectively to the public.
