The Japan Meteorological Agency (JMA) announced on October 27, 2026, that it has compiled and published data on the heavy rainfall caused by Typhoon No. 25, adding it to its ongoing series of reports on weather events that have caused disasters ^[1]. The agency publishes such compilations for weather events that caused major damage or attracted significant public attention, as part of its "Weather Cases That Caused Disasters" page on its website ^[1].

According to the JMA, Typhoon No. 25 brought record-breaking rainfall between September 19 and September 22, 2026 ^[1]. The agency reported that 24-hour and 48-hour precipitation totals at multiple observation points either set new all-time records or new records for the month of September ^[1].

Total rainfall during the event reached notable levels across a wide area, with the Izu Islands recording over 800 millimeters, Chiba and Shizuoka prefectures exceeding 500 millimeters, and areas including Kanagawa Prefecture surpassing 300 millimeters ^[1]. The JMA stated that this rainfall was record-setting in multiple locations and resulted in damage with significant social impact, which prompted the agency to compile and release the detailed data ^[1].

The JMA has made the full report available in PDF format on its website, along with related materials specifically covering the heavy rain event from September 19 to 22, 2026 ^[1]. Inquiries about the report can be directed to the agency's Atmosphere and Ocean Department, Weather Risk Countermeasures Division, as listed in the official notice ^[1].

For foreign residents in Japan, this report serves as an official record of the scale of rainfall experienced during Typhoon No. 25, particularly for those living in the Izu Islands, Chiba, Shizuoka, and Kanagawa prefectures, where the heaviest rainfall was recorded ^[1]. Residents in these areas who experienced flooding or other damage during this period may find the JMA's detailed data useful for understanding the severity of the event relative to historical records ^[1]. Those seeking further details, including the full data breakdown by location, should refer to the JMA's official publication linked in its press release ^[1].

Source credit 出典：「令和８年台風第25号による大雨の状況について～「災害をもたらした気象事例」に資料を掲載しました～」（気象庁）（https://www.jma.go.jp/jma/press/2610/27a/20261027_saimota.html）、PDL1.0（https://www.digital.go.jp/resources/open_data/public_data_license_v1.0）を加工してJapan News (j.apan.news)が作成 This article is Japan News's own English summary of the Japanese original. It has been translated and edited by Japan News; it is not an official translation, and the Japan Meteorological Agency did not write or review it.