Hot in Japanese: When to Use 暑い and 熱い

Japanese uses two common spellings of atsui, depending on what is hot:

• 暑い (あつい, atsui, hot weather): hot weather, air, or a hot room
• 熱い (あつい, atsui, hot object): a hot object, food, drink, body, or strong feeling

湯 (ゆ, yu, hot water) means hot water. It is a noun, not another way to write atsui.

暑い (atsui, hot weather) vs 熱い (atsui, hot object) at a glance

Both words sound the same. The kanji tells you which kind of heat you mean.

Examples with 暑い (atsui, hot weather)

Use 暑い (atsui, hot) when the weather or surrounding air makes a person feel hot.

• 今日はとても暑いです。
  Kyō wa totemo atsui desu.
  It is very hot today.
• この部屋は暑いです。
  Kono heya wa atsui desu.
  This room is hot.
• 日本の夏は暑いです。
  Nihon no natsu wa atsui desu.
  Summer in Japan is hot.

Examples with 熱い (atsui, hot object)

Use 熱い (atsui, hot) for something with a high temperature that you can touch, eat, or drink. It can also describe a body that feels hot or a strong, passionate feeling.

• スープが熱いです。
  Sūpu ga atsui desu.
  The soup is hot.
• この鍋は熱いです。
  Kono nabe wa atsui desu.
  This pot is hot.
• 体が熱いです。
  Karada ga atsui desu.
  My body feels hot.
• 彼は仕事に熱い思いを持っています。
  Kare wa shigoto ni atsui omoi o motte imasu.
  He has strong feelings about his work.

Where does 湯 (yu, hot water) fit?

湯 (ゆ, yu, hot water) means hot water. In everyday conversation, you will often hear お湯 (おゆ, oyu, hot water). The お makes the word sound more polite and natural in many ordinary situations.

お湯を沸かす (おゆをわかす, oyu o wakasu, to heat or boil water) does not specifically mean preparing a bath.

Related heat words

熱がある (ねつがある, netsu ga aru, to have a fever) and 熱が出る (ねつがでる, netsu ga deru, to develop a fever) are common expressions.

A quick way to choose

1. Is the weather, air, season, or room hot? Use 暑い (atsui, hot weather).
2. Is an object, food, drink, body, or feeling hot? Use 熱い (atsui, hot object).
3. Do you mean hot water as a noun? Use お湯 (oyu, hot water) or 湯 (yu, hot water).

If you mean fire rather than temperature, use 火 (hi, fire) for fire in general and 炎 (honō, flame) for a visible flame.