Disaster Prevention Weather Information: Encourage Evacuation by Using New Names

Editorial

16:34 JST, May 29, 2026

It is ideal for disaster prevention information to be easily understood and lead to residents evacuating. It is important to devise ways to disseminate information so that it reaches the public.

The Japan Meteorological Agency has reorganized its system and established the “disaster prevention weather information,” a five-level system of warnings and advisories that will be issued during four types of disasters — river flooding, heavy rain, landslides and storm surges.

Level 5, the highest level of danger, is an “emergency warning,” indicating a situation in which securing one’s own safety is necessary, such as moving to a safer room if one is at home.

The Level 4 “urgent warning” is the level at which everyone must evacuate from dangerous locations. Elderly people and others who require more time to leave are urged to start evacuating at the Level 3 “warning” stage.

The JMA is to be commended for unifying the names of information, which had varied depending on the type of disaster — such as heavy rain or landslides — and organizing them into a simple framework combined with using Levels 1 through 5. It can be said that the system has become easier to understand.

Local governments make the decision on whether to actually issue evacuation directives to residents based on disaster prevention weather information. However, if the disaster prevention weather information makes it easier for residents to directly perceive the degree of danger, it will likely lead to them evacuating earlier.

The turning point that prompted a review of disaster prevention information was the heavy rain in western Japan in 2018. Although the JMA issued such warnings as emergency heavy rain warnings and municipalities called for evacuations, the messages failed to convey a sufficient sense of urgency. As a result, residents did not feel urged to evacuate, leading to a large number of deaths.

Even if the central and local governments disseminate a wide variety of information, it will only cause confusion if residents cannot fully comprehend the level of danger. For this reason, “evacuation advisories” and “evacuation directives,” which had been criticized as confusing, were unified into “evacuation directives” in 2021.

On the other hand, with the advancement of observation technologies, it has become possible to forecast phenomena like localized linear rainbands, and the amount of information related to weather and disaster prevention is actually rising.

The challenge lies in how to convey crucial, life-saving information in an easily understandable manner in the event of an emergency. In the future, one option might be to simplify information by using only numbers, such as Level 1 through 5, without using terms like “warning” and “advisory.”

The arrival of the rainy season is just around the corner. Due to global warming, the country has been hit by record-breaking heavy rains almost every year in recent years, causing damage in various regions.

It is important for residents to be proactive, such as regularly thinking about what to do by referring to information such as forecasts on Kikikuru, the JMA’s risk map website, rather than just waiting for local governments to issue evacuation directives.

(From The Yomiuri Shimbun, May 29, 2026)