猛暑日(もうしょび)

もうしょび
noun
extremely hot day (over 35°C)
weather
1. extremely hot day (over 35°C)
A weather term used in Japan for days when the maximum temperature reaches 35°C (95°F) or higher.
今日(きょう)は猛暑日(もうしょび)になる予報(よほう)だ。
The forecast says today will be an extremely hot day.
今年(ことし)の夏(なつ)は猛暑日(もうしょび)が多(おお)かった。
This summer had many extremely hot days.
猛暑日(もうしょび)は熱中症(ねっちゅうしょう)に注意(ちゅうい)が必要(ひつよう)だ。
On extremely hot days, you need to be careful of heatstroke.

Types

The Japan Meteorological Agency's scale of hot days, by the day's maximum temperature:

  • 夏日(なつび): 25°C or higher (summer day)
  • 真夏日(まなつび): 30°C or higher (midsummer day)
  • 猛暑日(もうしょび): 35°C or higher
  • 酷暑日(こくしょび): 40°C or higher (a newer term)

Related words

Usage

Frequently appears in weather forecasts and news during summer. Often used alongside 熱中症(ねっちゅうしょう) warnings. An official 気象庁(きしょうちょう) term, adopted in 2007 as summer temperatures in Japan continued to rise.

Related Words

Related: 真夏日(まなつび) (hot day (over 30°C))
Related: 熱中症(ねっちゅうしょう) (heatstroke)
Related: 酷暑(こくしょ) (extreme heat)
Compare: 最高気温(さいこうきおん) (highest temperature)
general
Added 2026.2.3 11:36 · Revised 2026.10.4 3:59
09500/09622_moushobi