People walking at the iconic scramble crossing in Tokyo's Shibuya Ward amid intense heat on June 28, 2025. Photo: Jiji Press
The previous June high was 15,969 cases logged in 2022.
Many areas across the country experienced maximum temperatures of 35 degrees Celsius or higher on multiple days last month.
Of those hospitalized, 10,342 were aged 65 or over, accounting for about 60 pct of the total.
The largest number, of 6,819 cases, occurred at home or in other residential settings, followed by 3,404 cases on roads.
The agency is calling on people to stay home on days when a heatstroke alert is issued and to use air conditioners or fans appropriately.
