Originally written by:Mallory MoenchandBBC Weather
Link to the article: https://www.bbc.com/news/articles/crr185nx0n9o
In response to increasingly severe summer temperatures, Japan has officially introduced a new term to describe days when temperatures soar above 40°C. The move comes after a blistering summer that pushed the country’s weather patterns into uncharted territory and raised growing concerns about public health, infrastructure, and climate resilience.
The Japan Meteorological Agency (JMA) announced the new classification to better communicate the dangers associated with extreme heat. While Japan has long used terms like “mousho-bi” (extremely hot day, above 35°C), the increasing frequency of temperatures crossing the 40°C threshold has made it necessary to adopt a more urgent and distinct label.
This change reflects a broader shift in how authorities are addressing the realities of climate change. Experts say that rising global temperatures are making extreme weather events more frequent and intense, with Japan experiencing longer heatwaves, higher humidity, and record-breaking daytime highs.
The newly coined term aims to improve public awareness and encourage timely precautions, particularly for vulnerable groups such as the elderly and young children. During the recent summer, hospitals across the country reported a surge in cases of heatstroke, prompting renewed calls for stronger safety measures.
Government officials are also using this initiative to reinforce heat-related guidelines, including hydration, limiting outdoor activity during peak hours, and the use of cooling shelters in urban areas. Local governments have already begun incorporating the new terminology into weather alerts and emergency broadcasts.
As Japan adapts to a warming climate, the introduction of this term marks a significant step in acknowledging the severity of extreme heat and preparing citizens for what may become a more common reality in the years ahead.
