Japan has introduced a new term, 'Kokushobi', to describe the country's increasingly severe heat conditions. The Japan Meteorological Agency (JMA) announced the term after last summer’s record-breaking temperatures reached up to 40 degrees Celsius. The word combines 'koku', meaning 'extremely high', to denote days of intense heat. The decision followed a national online survey conducted between February and March, in which 478,000 people participated to select the most fitting term from 13 options.

According to the Japan Times, Japan experienced its hottest summer since temperature records began in 1898, with the 2025 season averaging 2.36 degrees Celsius above normal. During June to August, nine days exceeded 40 degrees, and Isesaki city recorded a national high of 41.8 degrees Celsius. Tokyo saw 25 days above 35 degrees, while Kyoto recorded 52 such days. The JMA has forecast that temperatures from June to August this year will again remain above normal.

The new terminology reflects Japan’s growing concern over climate change, as fossil fuel use and human activities continue to drive global warming.