真夏日(まなつび)

まなつび
noun
hot summer day (over 30°C)
1. hot summer day
A day when the maximum temperature reaches 30°C (86°F) or higher. An official meteorological term used by the Japan Meteorological Agency.
今日(きょう)は真夏日(まなつび)になる予報(よほう)だ。
Today is forecast to be a hot summer day.
真夏日(まなつび)が続(つづ)いている。
The hot summer days continue.
今年(ことし)の真夏日(まなつび)の日数(にっすう)は過去最多(かこさいた)を記録(きろく)した。
This year recorded the highest number of hot summer days in history.

An official meteorological term used by the Japan Meteorological Agency (気象庁(きしょうちょう)) to classify days when the maximum temperature reaches 30°C or higher.

WORD FORMATION:
真夏(まなつ) (midsummer) + 日(び) (day)

METEOROLOGICAL TERMS:

Japan has official categories for hot days:

  • 夏日(なつび): 25°C or above
  • 真夏日(まなつび): 30°C or above
  • 猛暑日(もうしょび): 35°C or above

USAGE:
Commonly appears in weather forecasts and news reports, especially during summer months. The number of 真夏日(まなつび) per year is tracked as a climate indicator.

RELATED TERMS:

  • 熱帯夜(ねったいや): tropical night (minimum above 25°C)
  • 猛暑(もうしょ): extreme heat
  • 酷暑(こくしょ): intense heat
general
Added 2026.2.5 21:58 · Revised 2026.3.28 18:49
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