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Disclaimer
Educational guide, not an alert service: no live data. Always follow official instructions from JMA, your municipality, police, fire and staff. In an emergency, protect yourself first.
Data as of 2026-10-17 from official JMA, Cabinet Office, Cabinet Secretariat (J-ALERT) and Ministry of the Environment pages, with official names from the JMA multilingual dictionary (2026-03-26). Not affiliated with JMA or any government agency.
What this is
A free, unofficial educational decoder. It matches the text of a Japanese emergency alert you paste (or an alert type you pick) against a dated copy (as of 2026-10-17) of the official alert system published by the Japan Meteorological Agency (JMA), the Cabinet Office, the Cabinet Secretariat (J-ALERT) and the Ministry of the Environment, and shows the general meaning, the alert level and the general actions those agencies recommend. Official names in other languages come from JMA's multilingual dictionary. It is not affiliated with any of these agencies.
What it is not
It is not an alert or warning service, it has no live data, and it cannot tell you whether an alert is in effect for your location right now or how dangerous your exact spot is. Text matching can be wrong or incomplete; a recognised name does not mean the rest of the message was understood. The general actions shown do not replace the instructions of JMA, your municipality, police, fire services, transport or venue staff. In an emergency, protect yourself first and follow official instructions; check JMA's live maps, your phone's emergency alerts, local radio or TV and your municipality's announcements.
Rules change
Japan renamed its heavy-rain, flood, landslide and storm-surge warnings on 2026-05-29, and agencies adjust criteria and wording over time. This page reflects the sources below as of 2026-10-17 and may lag behind later changes.
Sources
- https://www.jma.go.jp/jma/kishou/know/bosai/keiho-update2026/index.html
- https://www.jma.go.jp/jma/kishou/know/bosai/keiho-update2026/pdf/english_info2026.pdf
- https://www.jma.go.jp/jma/kishou/know/bosai/keiho-update2026/pdf/outline_info2026.pdf
- https://www.jma.go.jp/jma/kishou/know/bosai/keiho-update2026/pdf/info2026_english_leaflet.pdf
- https://www.jma.go.jp/jma/kishou/know/bosai/keiho-update2026/pdf/wxinfo_info2026.pdf
- https://www.jma.go.jp/jma/press/2604/14b/20260414_taikeiseiri.html
- https://www.jma.go.jp/jma/kishou/know/bosai/alertlevel.html
- https://www.jma.go.jp/jma/en/Emergency_Warning/ew_index.html
- https://www.jma.go.jp/jma/kishou/know/jishin/eew/index.html
- https://www.jma.go.jp/jma/kishou/know/jishin/eew/shikumi/shousai.html
- https://www.jma.go.jp/jma/kishou/know/jishin/eew/koudou/koudou.html
- https://www.jma.go.jp/jma/en/Activities/eew1.html
- https://www.jma.go.jp/jma/press/2610/16c/202610161730.html
- https://www.jma.go.jp/jma/press/2610/16d/kaisetsu202610162240.pdf
- https://www.jma.go.jp/jma/en/Activities/inttable.html
- https://www.data.jma.go.jp/eqev/data/joho/tsunamiinfo.html
- https://www.jma.go.jp/jma/en/Activities/earthquake.html
- https://www.jma.go.jp/jma/kishou/know/jishin/nteq/index.html
- https://www.jma.go.jp/jma/kishou/know/jishin/nceq_info_criterion.html
- https://www.data.jma.go.jp/developer/multilingual.html
- https://www.jma.go.jp/jma/kishou/know/jishin/tagengo/tagengo.html
- https://www.bousai.go.jp/jishin/nankai/rinji/index4.html
- https://www.bousai.go.jp/jishin/nihonkaiko_chishima/hokkaido/index3.html
- https://www.bousai.go.jp/oukyu/hinanjouhou/r3_hinanjouhou_guideline/
- https://www.bousai.go.jp/kyoiku/gaikoku/pdf/02_training_material_EN.pdf
- https://www.kokuminhogo.go.jp/en/pc-index_e.html
- https://www.kokuminhogo.go.jp/en/pdf/action(English).pdf
- https://www.wbgt.env.go.jp/en/
- https://www.data.jma.go.jp/vois/data/tokyo/STOCK/kaisetsu/English/level.html
Your data
Text you paste is decoded in your browser (or by the API if you call it) and is not stored. No login, no database. Anonymous page-view analytics only.