Japan Logs Its First 'Cruelly Hot Day' as Temperatures Top 40C

New weather-agency term marks a summer of record highs, prompting Tokyo to urge office workers into shorts

Japan recorded its first official kokushobi, or "cruelly hot day," on Tuesday, the newly coined term for when temperatures exceed 40 degrees Celsius (104 Fahrenheit), the BBC and the Guardian reported.

The Japan Meteorological Agency introduced the designation in April to warn the public about heat dangers that were once freak weather events but have become increasingly common. The central cities of Gujo and Tajimi in Gifu prefecture, along with Toyota in Aichi prefecture, all hit 40C, with Gujo's reading and Toyota's 40.1C setting all-time highs at their respective weather stations, the Guardian reported.

The extreme heat has prompted Tokyo's metropolitan government to urge male office workers to ditch suits and ties for T-shirts, sneakers and shorts, according to the BBC. The push has drawn a mixed reaction; some women have described the shift as "leg hair harassment," the BBC reported.

The scorching temperatures are part of a broader pattern of extreme heat straining infrastructure and daily life across the country this summer, as authorities continue refining public warnings to help residents cope with conditions that are testing the limits of Japan's traditional workplace norms and public health guidance.

— Compiled from reporting by the Guardian and the BBC.