Japan has recorded its first official 'cruelly hot day' (kokushobi), a term for days when temperatures surpass 40C, as a severe heatwave grips the nation. The mercury exceeded 40C in Gifu and Aichi prefectures, while central Tokyo reached 34C on 14 July 2026. The extreme heat has resulted in heatstroke deaths and reduced crop yields across the country.
Heatwave impacts cities and daily life
Images from Tokyo and surrounding areas show residents and visitors struggling to cope with the blistering conditions. Young women in Harajuku used handheld fans, and pedestrians shielded themselves with umbrellas. At Sensoji temple, visitors sought refuge from the sun. In Kumagaya, northwest of Tokyo, students tried to keep cool while watching a summer festival as temperatures hit 36C.
Government officials in the Tokyo Metropolitan Government building have adopted casual dress as part of the expanded 'Cool Biz' initiative, which now includes shorts to address increasingly hot summers.
Innovative cooling measures
At the Extreme Heat Countermeasures expo, innovative products were showcased, including an inflatable dog wearing fan-equipped pet clothing and a hands-free backpack parasol. A man was spotted wearing an air-conditioned jacket fitted with cooling fans in Tokyo on 15 July. Others took breaks under cooling mist sprays during the heatwave.
Pet owners also took steps to keep their companions sheltered from the blazing sun. The heatwave has prompted widespread adaptation, with authorities widening the 'Cool Biz' dress code to include more casual attire.
According to reports, the term kokushobi (酷暑日) has been coined to describe days exceeding 40C, as Japan faces rising temperatures linked to the climate crisis. The heatwave is expected to continue, with authorities urging precautions against heatstroke.
