Skip to content

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. Full disclaimer

FreeJapan Alert Decoder

Japan alert decoder · レベル4高潮危険警報

Level 4 Urgent Warning (Storm Surge) · Level 4

Evacuate now from dangerous places · official rules as of 2026-10-17

← Decode another alert · Earthquake Early Warning on a train

Or tap one

Where are you? (optional)
Level 4Evacuate now from dangerous places

レベル4高潮危険警報

Level 4 Urgent Warning (Storm Surge)

Purple, Alert Level 4 equivalent (a new class since 2026-05-29): a disaster could happen at any time. Everyone in a dangerous area should evacuate now ("evacuate by Level 4"). Municipalities issue 避難指示 (Evacuation Instruction) at this level. Hazard: sea water flooding the coast during a typhoon or deep low.

What to do now

  1. Evacuate now from dangerous areas to a shelter, or to a safe friend's house or hotel outside the danger zone.
  2. If it is already dangerous outside, move to a higher floor or a room away from slopes.
  3. Follow your municipality's evacuation instruction.
  4. Stay away from the coast, harbours and low coastal land.
  • Japan's rule of thumb: evacuate by Level 4 (purple). Don't wait for Level 5.

Issued by: JMA. Live status: JMA warnings map (English)JMA earthquake information (English)JMA tsunami information (English)

source 1source 2source 3

Share on X

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.

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.