When heavy rain, flooding, or landslide risk builds in Japan, information is shared using a simple 5-level scale called 警戒レベル (keikai reberu, "warning levels"). The scale runs from 1 to 5, and each number tells you clearly what stage the situation has reached and what action fits that stage. Knowing the five levels in advance means you can respond calmly instead of trying to interpret unfamiliar terms during a storm.
The Japan Meteorological Agency (JMA) issues the weather information that sits behind the scale, while your local municipality (your city, town, or ward office) issues the evacuation-related levels for your area. The two work together: JMA describes the hazard, and the municipality decides when to tell residents in specific districts to act.
The five warning levels at a glance
| Level | Name (Japanese) | What it means for you |
|---|---|---|
| 1 | 早期注意情報 | Be aware. Risk is possible in the coming days. Check the latest forecasts. |
| 2 | 注意報 | Review your evacuation routes and your local hazard map now. |
| 3 | 高齢者等避難 | Older residents and anyone who needs more time should start evacuating. Others should prepare. |
| 4 | 避難指示 | Everyone in the target area should evacuate to a safe place. |
| 5 | 緊急安全確保 | A disaster may already be occurring. Take the best action available right now to protect your life. |
Understanding each level
Level 1 is an early heads-up. It simply asks you to stay aware and keep an eye on the forecast. Level 2 is the moment to look up your hazard map and confirm where you would go and by which route. Doing this early, while conditions are still calm, is far easier than doing it in the rain.
Level 3 (高齢者等避難) is directed at people who take longer to move: elderly residents, people with disabilities, families with small children, and anyone assisting them. If that describes your household, this is your signal to leave. Everyone else should finish preparing. Level 4 (避難指示) means everyone in the named area should evacuate. There is no higher evacuation instruction than Level 4, so treat it as the point to complete your move to safety.
Level 5 (緊急安全確保) means a disaster may already be underway and safe evacuation may no longer be possible. At this stage the advice shifts to securing your safety immediately wherever you are, for example moving to a higher floor or the side of the building away from a slope. Level 5 is not always issued, so you should never wait for it before acting on Level 3 or 4.
How residents receive the levels
Alerts reach people through several channels, and it helps to have more than one set up:
- エリアメール / 緊急速報メール: emergency messages pushed automatically to mobile phones in the affected area. Most phones sold in Japan receive these by default.
- Yahoo! 防災速報 (Yahoo Bosai): a free app with English-friendly settings that sends alerts for your registered locations.
- NHK: television, radio, and the NHK News/Disaster app carry warnings and evacuation information.
- Local municipal alerts: outdoor loudspeakers (防災行政無線), city apps, and email or LINE sign-ups run by your ward or city.
Because emergency messages often arrive first in Japanese, it is worth setting up your alert apps and learning the five level names before anything happens. A few minutes of preparation now removes a lot of guesswork later. If you commute or work away from home, keep a small readiness kit where you spend your day; see our office and commute kit guide. For household stocking, our 7-day plan for a family covers food and water.
The warning-level scale applies to weather-driven hazards like floods and landslides. Earthquake-related information, including the separate Nankai Trough advisory, works differently and is worth reading about on its own.
Sources
The five-level scale is defined by the Japan Meteorological Agency (JMA) and the Cabinet Office (内閣府), which sets the national guidelines for evacuation information. Refer to the JMA and Cabinet Office (Disaster Management) websites for the current official wording and any future updates.