Japan issues widespread heatstroke alerts as cities pass 40C

Japanese cities are experiencing days above 40C under a new meteorological term created this year to warn people about intense heat, while heatstroke alerts have been issued across almost the whole country.

The Japan Meteorological Agency said three central cities recorded temperatures above the threshold on Tuesday. The term is "kokushobi", translated in the report as "cruelly hot day". On Wednesday, other areas, including Nagoya and communities near Tokyo, were facing temperatures approaching or exceeding 40C.

The agency issued heatstroke alerts in 41 of Japan's 47 prefectures and urged people, especially elderly residents, to stay cool.

In rural Tochigi, north of Tokyo, an 85-year-old man was found collapsed inside a greenhouse on his farm on Tuesday and was later confirmed dead. A local fire spokeswoman said the greenhouse was extremely hot inside.

The Fire and Disaster Management Agency urged the public to regard the extreme heat as a disaster. It said temperatures had been rising since mid-July and severe heat was expected to continue nationwide. The agency said many people were being taken to hospitals or dying as a result of heatstroke.

Scientists say human-induced climate change is increasing the frequency and intensity of extreme heat events in Japan and elsewhere. The source said Japan had its hottest summer on record last year, and that the country's highest recorded temperature was 41.8C in Isesaki, north of Tokyo, on August 5, 2025.