Trending Now - Japan Coined a Term for Its Extreme Heat Wave Days

WHO:

Phys.org - Japan's weather agency is involved in the naming of heat wave days.

WHAT:

BBC News - The term "kokusho-bi" translates to "brutally hot" or "severely hot" in addition to "cruelly hot."

BBC News - The announcement of the new term follows Japan experiencing its hottest summer on record in 2025.

Phys.org - Japan has coined the term "kokusho-bi," meaning "cruelly hot," for days with blistering temperatures rising to 40°C and above.

Bloomberg Markets - The weather agency has formally adopted this new name ahead of the summer of 2026.

WHERE:

Phys.org - The term is being used in Japan.

WHEN:

Phys.org - The announcement was made on Friday, April 15th, 2026.

WHY:

Phys.org - The new term reflects the increasing frequency of heat wave days in Japan.

HOW:

Bloomberg Markets - The weather agency has implemented a formal naming process for extreme heat days.

(UPDATED April 17, 2026 21:13 UTC)

Japan has introduced a new term, "kokusho-bi," which translates to "brutally hot," "severely hot," and "cruelly hot." This announcement comes after the country experienced its hottest summer on record in 2025. The term reflects the extreme heat conditions that have become increasingly prevalent.

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(UPDATED April 17, 2026 15:19 UTC)

Japan's weather agency has officially adopted the term "kokusho-bi," which translates to "cruelly hot," to describe days when temperatures soar to 40 degrees Celsius and above. This announcement was made on Wednesday, as part of a new formal naming process for extreme heat days, reflecting the growing frequency of heat waves in the country. The term will be used throughout Japan as the summer of 2026 approaches.