Japan swelters in first extreme heatwave of the year

Japan sizzled under sweltering, life-threatening heat on Wednesday, with temperatures expected to top 40 degrees Celsius (104 degrees Fahrenheit) in some cities in what the government has newly designated as a "brutally hot day."

The weather agency issued heat stroke alerts for much of the country, forecasting a second straight day of "kokushobi" - literally meaning brutally hot day - with temperatures expected to reach 40 C in Kumagaya, north of Tokyo, and Nagoya, in central Japan.

Authorities urged residents to use air conditioning liberally, hydrate regularly and avoid spending long hours outdoors.

Japan has experienced increasingly severe summers in recent years, with the country recording its all-time high temperature of 41.8 C last year.

Even before this week's extreme heat, 4,580 people were taken to hospital between July 6 and 12, including seven who later died, according to the latest data available from the Fire and Disaster Management Agency.

The weather agency this year introduced the "kokushobi" category for days when temperatures reach 40 C or higher, reflecting the growing frequency of extreme heat. More than 100,000 people were taken to hospital for heatstroke during the 2025 summer season, according to government data.

-Reporting by Chang-Ran Kim; Editing by Thomas Derpinghaus/Reuters