酷こく暑しょ日び

noun

extremely hot day (≥35°C)

Colloquial term for a day when the maximum temperature reaches 35°C or higher. Compare with 猛暑日, which is the official JMA term for the same threshold.

See also: 猛暑日

• 今日きょうは酷こく暑しょ日びになる見み込こみで、熱ねっ中ちゅう症しょうに警けい戒かいが必ひつ要ようです。

  Today is expected to be an extremely hot day (≥35°C), so heatstroke precautions are necessary.

noun

extremely hot day (≥40°C)

Used by some agencies for days when the maximum temperature reaches 40°C or higher. This usage is less common and not standardized across all meteorological organizations.

• 一いち部ぶの機き関かんでは、最さい高こう気き温おんが40度どを超こえる日ひを酷こく暑しょ日びと定てい義ぎしている。

  Some agencies define a day with a maximum temperature exceeding 40°C as a 酷暑日.