TOKYO - Three cities in central Japan on Tuesday reached 40 C, officially marking the country's first "kokushobi," or "cruelly hot day," since the weather agency introduced the term earlier this year to warn the public of extreme heat.

As a high-pressure system covered much of the Japanese archipelago, Tajimi and Gujo in Gifu Prefecture recorded temperatures of 40.3 C and 40.0 C, respectively, while the mercury in Toyoda in Aichi Prefecture climbed to 40.1 C, according to the Japan Meteorological Agency.

Related coverage: