Scorching heat of 35 degrees Celsius or above was observed in many parts of Japan on Friday, with some areas recording the highest-ever temperatures for September.
The Japan Meteorological Agency said a high-pressure system covering areas in eastern and western Japan on the southern side of a front has brought sunny conditions.
It said the mercury rose to dangerous highs of 39.2 degrees in Shizuoka City, and 38 degrees in Obama City in Fukui Prefecture and Toyooka City in Hyogo Prefecture.
The daytime maximum temperature reached 35 degrees or higher at 143 locations, nearly one-sixth of the total number of observation points in Japan. They include 37.9 degrees in Tottori City, and 37.8 degrees in Otsuki City in Yamanashi Prefecture and Ogaki City in Gifu Prefecture.
At 39 observation points including Shizuoka City, temperatures soared as high as or higher than the record for September.
Dazaifu City in Fukuoka Prefecture recorded 35 degrees, marking 62 days of 35 degrees or higher.
Weather officials say temperatures are expected to be lower on Saturday in western Japan and other areas, but some parts, mainly in eastern Japan, may see another day of scorching heat of 35 degrees or more.
Daytime highs are forecast to reach 36 degrees in central Tokyo, Saitama City and Shizuoka City, 35 degrees in Oita City and Takamatsu City, and 34 degrees in Chiba City, Nagoya City and Kumamoto City.
Heatstroke alerts have been issued for Chiba and Kumamoto prefectures, and for Kagoshima Prefecture except for the Amami region.
People in those areas are being advised to use air conditioners, drink enough liquids and take in an adequate amount of salt.