With rising incidents of temperatures exceeding 40 degrees Celsius during the summer, Japan's Meteorological Agency announced on the 27th that it is seeking new names for such extreme heat days. The agency has listed 13 candidate names, including "enjo-bi" (fire heat day), "koku-sho-bi" (intense heat day), and "cho-mojo-bi" (super intense heat day). Individuals are invited to propose names that are not included in the list, enhancing public engagement in acknowledging the severity of rising temperatures. The agency aims to implement these terms for weather forecasts and reports this summer.

The frequency of days exceeding 40 degrees Celsius has been increasing, with instances recorded every year since 2018. The highest temperature recorded in Japan was 41.8 degrees Celsius on August 5, 2025, in Isesaki City, Gunma Prefecture. Currently, established terms like "natsu-bi" (summer day) for temperatures over 25 degrees, "midsummer day" for 30 degrees, and "mojo-bi" (intense heat day) for 35 degrees are in use. The term "mojo-bi" was incorporated into weather jargon in 2007 to better communicate extreme temperature events.

Public voting for the proposed new names is open until March 29, accessible through the Meteorological Agency's website. The top suggestions will be evaluated through consultations with weather and language experts to finalize the most suitable term. A spokesperson emphasized the initiative aims to raise awareness about the increasing heat and the impact of global warming, encouraging the public to be more vigilant about heat-related conditions in the future.