TOKYO (Jiji Press)--Temperatures exceeded 40 degrees Celsius in central Japan on Tuesday, marking the first "kokushobi," or cruelly hot day, this year, according to the Japan Meteorological Agency.

The city of Tajimi, Gifu Prefecture, recorded 40.3 degrees, followed by the city of Toyota in the neighboring prefecture of Aichi with 40.1 degrees and the Hachiman district of the Gifu city of Gujo with 40.0 degrees.

The term "kokushobi" was introduced in April for days when the mercury reaches 40 degrees or higher.

As many as 278, or about 30 pct, of all observation points across Japan saw temperatures rise to 35 degrees or higher, marking a "moshobi," or extremely hot day.

These locations included the Aichi capital of Nagoya with 39.7 degrees, the eastern city of Koga, Ibaraki Prefecture, with 39.6 degrees, the western city of Osaka with 37.1 degrees, Tokyo's Chiyoda Ward with 36.4 degrees, the northeastern city of Sendai, Miyagi Prefecture, with 35.6 degrees, and the southwestern city of Fukuoka with 35.3 degrees.

In the city of Kumagaya, Saitama Prefecture, north of Tokyo, the mercury was forecast to reach 40 degrees but stopped at 38.6 degrees. Still, Kumagaya, along with Nagoya and the city of Kofu, Yamanashi Prefecture, west of Tokyo, is expected to record a kokushobi on Wednesday and Thursday. The city of Gifu is expected to do so on Thursday.

With a high-pressure system stretching from the southern part of the Tohoku northeastern region to the Kyushu southwestern region, temperatures soared especially in the Kanto eastern region and the Tokai central region on Tuesday, prompting the agency to issue heatstroke alerts for all prefectures excluding some in Tohoku and the northernmost prefecture of Hokkaido.