Japanese weather officials are warning the public about heatstroke as extremely hot weather continues on Sunday.
Several elderly people have died of possible heatstroke.
The Meteorological Agency says a high-pressure system in the Pacific Ocean continues to cover wide areas across western and eastern Japan, raising temperatures.
The mercury reached 40 degrees Celsius in Shizuoka City in central Japan at 1:18 p.m., the highest ever in the city since the agency started keeping records in 1940.
It is the first time temperatures reached 40 in Japan since August 10 of last year in Komatsu City, Ishikawa Prefecture on the Sea of Japan coast.
Sunday's daytime high reached 39.8 in Shimonita Town, Gunma Prefecture, 38.8 in the town of Namie, Fukushima Prefecture and the cities of Otsuki in Yamanashi Prefecture and Hamamatsu in Shizuoka Prefecture.
The agency and the Environment Ministry have issued heatstroke alerts for 26 prefectures from Kanto to Okinawa, including Tokyo.
People are urged to use air conditioners appropriately, and avoid unnecessary outings and exercise.
Families are advised to give special attention to the elderly and children who are vulnerable to heatstroke.