The Japan Meteorological Agency and the national government will launch a new disaster-weather information system on May 28, 2026 [1].
The update aims to eliminate confusion caused by inconsistent warning names and levels across different types of disasters. By providing a standardized numeric scale, the government intends to give the public a clearer cue for when to evacuate during extreme weather events [1, 6].
The new system assigns a five-level numeric scale, ranging from one to five [1, 3]. This scale will be applied to four specific disaster categories: river floods, heavy rain, landslides, and storm surges [1, 2].
As part of this restructuring, the agency created a new "danger warning," known in Japanese as *kiken keihō*, which is designated as level four [3, 4]. This specific tier is designed to bridge the gap between standard alerts and the highest level of emergency notification.
Previously, the ranking of certain alerts was inconsistent. For example, a storm-surge special warning was ranked lower than a heavy-rain special warning [1, 6]. The numeric system removes these discrepancies by centering the urgency on the level number rather than the specific name of the weather event.
Operation of the new system begins in the afternoon of May 28 [1, 2]. The rollout will occur nationwide across Japan [1, 2].
“The new system assigns a five-level numeric scale, ranging from one to five.”
This shift represents a move toward behavioral science in public safety, prioritizing intuitive numbering over complex terminology. By standardizing the urgency of different natural disasters—such as storm surges and landslides—into a single 1-5 scale, Japan is attempting to reduce the cognitive load on citizens during crises, potentially speeding up evacuation times and reducing casualties.
