A Japanese word for August : net tai ya

It is well known that Japanese summer can be unbearably hot and humid, especially during July and August. All day long people will drag themselves from building’s shadow to the cool undergrounds of Tokyo metro and shopping mall, resting from the sultriness.

One would hope that at sundown, the heat would become mild… Alas! During summer, when night falls, temperature doesn’t go down. And there is a Japanese word to describe those nights during which the minimum temperature is 25 degrees or higher: nettaiya.

外気温が摂氏 25 度より下がらない暑い夜を日本では熱帯夜とよぶ.
A hot night when the temperature does not fall below 25°C outdoors is called a ‘tropical night’ in Japan.

This Japanese word comes from “nettai” meaning “the tropics”. This word relates to hot regions such as the Amazon, the Caribbean or the Philippines. The word nettai is then combined with the kanji for night, 夜, whose reading here is “ya”. Nettaiya can be directly translated as “tropical night”, but a more accurate translation would be “sweltering night“. And it makes people miserable every summer in Japan!

According to the Japan Meteorology Agency, since 20 years, the number of consecutive sweltering nights have kept rising to an average of 30 hot nights per year in Japan. All of them take place during July and August.

It is said that the augmentation of hot nights is a consequence of the global warming and the effect of urban heat islands. Metropolitain area such as Tokyo, stay hot during nights, due to human activity and concrete buildings. The concrete buildings absorbe the heat during daytime and do not cool off at night, keeping temperature at high level in the cities.

During the nettaiya, people suffer a lot and can hardly sleep. But even more than sleeping problem, nettaiya along with natsubate (夏バテ) have proven to be dangerous, particularly to elderly people, as they increases the risk of heat stroke. You have no choice but to use air conditioning or a fan, and try to refresh yourself to be able to rest.

When would you use this Japanese word? Well… We can think of one really practical example! When you arrive to your working place, looking exhausted, you can just tell your colleagues that the nettaiya kept you up all night.

How to use this Japanese word in conversation?

Japanese Example
A: 大変ですね。これで 3 夜連続の熱帯夜です.
English Translation
A: Good morning. You look really sleepy. What’s going on?
B: The nettaiya keep going night after night and I just can’t sleep.
A: Ah, it is hard. We had sweltering nights, for three consecutive days.

Japanese Example

English Translation
A: Sweltering nights in summer season only last for about ten days.

Nettaiya may make you dream about the tropical nights at an exotic resort, but Japanese’s nettaiya are way different from a vacation in the tropics! Have you heard this Japanese word before? Did you experience nettaiya night in Japan?

Credit CC-BY-NC: Ishibashi Shunsuke
Title: 中目黒夏まつり

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