At least nine people died and 28 were injured across the nation Sunday during leisure activities on land and at sea, a tally shows.
The hot, sunny weather across much of the country prompted many people to go outdoors for recreation, while crowds swamped amusement facilities with the advent of summer vacation at many schools over the weekend.
The fatalities included a 16-year-old Brazilian high school student who drowned at a beach in Takahama, Fukui Prefecture, and a hiker in Yamanashi Prefecture believed to be a 70-year-old Tokyo man who was found collapsed on a mountain trail and confirmed dead while being taken to hospital.
Scorching heat continued to grip much of Japan, with temperatures reaching 39 in some cities. Central Tokyo recorded its highest temperature of the year at 35.6 on Sunday, according to the Meteorological Agency.