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6 clusters · 7 sources · 34 days · First seen · Last updated

Severe weather and flooding across Japan

Overview

Following previous warnings in Kumamoto, Aomori, Akita, and Kyoto, weather alerts intensified across Japan in late August 2026.

On August 21, the Japan Meteorological Agency issued warnings for the Kanto-Koshin region and Tochigi Prefecture due to pressure troughs and warm, moist air. Projections included 24-hour rainfall of up to 80mm and hourly rates of 40mm, with risks of flooding, landslides, lightning, and hail. Simultaneously, a tornado advisory was released for Hiroshima Prefecture, and an early warning was issued for Osaka regarding potential heavy rain on August 22.

By August 22, severe localized ‘guerrilla rainstorms’ caused significant disruption. In the Kanto region, parts of Tokyo and Saitama received over 120mm of rain in a single hour, triggering ‘record-breaking short-term heavy rain’ alerts. In Tokyo, rising water levels in the Zenpukuji and Kanda Rivers prompted Level 4 flood danger warnings, and a road collapse was reported in Chiyoda Ward.

As of August 23, unstable conditions are expected to persist. Meteorological offices have issued early warnings for the Kinki region, noting that heavy rain warnings may be issued for Osaka, Hyogo, and southern Kyoto prefectures on August 24. Residents in these areas are advised to prepare for sudden, intense thunderstorms and potential flooding.

Entities

Japan Meteorological Agency · Kanto-Koshin region · Tochigi Prefecture · Osaka · Kyoto

Timeline

  1. about 7 hours ago

    [INTERNATIONAL] 2 sources
    Japan weather: Heavy rainstorms cause flooding in Kanto and warnings for Kinki

    Severe localized rainstorms have caused flooding and road damage in the Kanto region, with heavy rain warnings expected for the Kinki region, including Osaka and Kyoto, through August 24.

  2. 3 days ago

    [INTERNATIONAL] 3 sources
    Japan weather alerts: Tornado warnings in Hiroshima and heavy rain risks in Osaka

    Japan Meteorological Agency issues tornado advisories for Hiroshima and warns of heavy rain and flooding risks in Osaka starting August 22.

  3. 3 days ago

    [INTERNATIONAL] 2 sources
    Japan weather alert: Heavy rain and flooding risks in Kanto-Koshin and Tochigi

    Heavy rain warnings have been issued for Japan's Kanto-Koshin region and Tochigi Prefecture, with risks of flooding, landslides, and lightning expected through the early hours of the 22nd.

  4. 15 days ago

    [INTERNATIONAL] 4 sources
    Japan weather: Heavy rain alerts issued for Yuzawa and Kyoto

    Heavy rain alerts have been issued in Japan, with Yuzawa City seeing 100mm of rain in one hour and Kyoto Prefecture facing risks of warning-level storms and localized thunderstorms.

  5. 15 days ago

    [INTERNATIONAL] 2 sources
    Heavy rain warnings issued for Kanto-Koshin and Tochigi regions

    Heavy rain warnings are in effect for Japan's Kanto-Koshin and Tochigi regions due to unstable weather, with risks of flooding, landslides, and intense thunderstorms through the early hours of the 10th.

  6. about 1 month ago

    [INTERNATIONAL] 5 sources
    Thunderstorm warnings issued for Kumamoto and Aomori prefectures in Japan

    Japan's weather agencies issued thunderstorm warnings for Kumamoto and a heavy‑rain/lighting advisory with farm safety guidance for Aomori on 21 July 2026.

Sources

blogdoperrone.blogosfera.uol.com.br · fnn.jp · fukuishimbun.co.jp · kyoto-np.co.jp · kyoto-np.jp · news.cube-soft.jp · shimotsuke.co.jp

This summary has been updated 4 times: see revision history