The Japanese language has a fascinating ability to express feelings, moods, and phenomena in a single word that would often require a whole sentence to describe in other languages.
A beautiful example is the word Ukiyo (浮世) – the "floating world". It expresses the idea of living in the present moment, appreciating the beauty of each passing experience, and letting go of everyday worries.
And, of course, the Japanese language also has its own words for natural and meteorological phenomena – including those that have become increasingly familiar around the world in recent years: extreme summer heat.
One of the expressions used in Japan to describe oppressive heat is Kokushobi (酷暑日, こくしょび).
What does Kokushobi mean?
Kokushobi can be translated as "a day of extreme heat" or "a day of severe, relentless heat.”"
The word is made up of three characters:
酷 (koku) – harsh, severe, extreme, merciless
暑 (sho) – heat, hot weather
日 (bi) – day
Literally, it means "a day of extreme heat."
In everyday language and the media, it is used to emphasise days when temperatures go beyond ordinary summer warmth and become truly exhausting.
How do the Japanese describe hot summer days?
Japanese meteorology distinguishes several levels of summer heat:
Natsubi (夏日) – a summer day when the maximum temperature reaches 25 °C or higher
Manatsubi (真夏日) – a true summer day when the temperature reaches 30 °C or higher
Mōshobi (猛暑日) – an extremely hot day when the temperature reaches 35 °C or higher
Mōshobi is the official meteorological term used in Japan. The word Kokushobi is rather a more expressive term, often used in the media and everyday communication to describe exceptionally harsh, intense, and exhausting heat.
Unfortunately, such days are no longer unusual in Japan or in many other parts of the world. During the hottest periods, temperatures regularly approach 40 °C, creating challenges for both people and nature.
How to stay refreshed during Kokushobi days?
In Japan, tea remains an important everyday ritual even during the hottest days of summer. It may sound surprising, but properly prepared tea can be a wonderful companion during hot weather.
One of the most popular summer preparations is cold brew tea – tea slowly infused in cold water.
This gentle method allows the delicate aromas and natural sweetness of the tea leaves to gradually develop, creating a refreshing and smooth drink with a softer taste and less bitterness. Japanese green teas, such as gyokuro and sencha, as well as darjeeling or many oolongs, are especially suitable for this preparation.
Cold tea is not only a refreshing drink – it is also a small summer ritual that invites us to slow down and enjoy the present moment.
We have written more about why hot tea can also have its place in summer in our article: Hot tea in summer? Yes, and here’s why.