Translation guide
In Japanese, expressing 'humidity' depends on whether you're talking about the weather, the amount of moisture in the air, or the uncomfortable feeling of dampness. The most common word is 湿度 (しつど), but for the oppressive summer humidity, 蒸し暑さ (むしあつさ) or the adjective 蒸し暑い (むしあつい) are more natural.
今日は湿度が高いです。
The humidity is high today.
蒸し暑い！
It's so humid!
Referring to the measurable amount of water vapor in the air, often used in weather forecasts or technical contexts.
The standard word for humidity as a measurable quantity. Used in weather reports, hygrometers, and everyday conversation about humidity levels.
今日は湿度が高いですね。
The humidity is high today, isn't it?
湿度計を見ると、80%だった。
When I looked at the hygrometer, it was 80%.
Refers to moisture in the air, often with a nuance of dampness or mustiness. Can be used for indoor humidity or the feeling of damp air.
この部屋は湿気が多い。
This room has a lot of humidity (is damp).
Describing the oppressive, sticky feeling of high humidity combined with heat, typical of Japanese summers.
The noun form meaning 'mugginess' or 'sultriness'. Used to talk about the uncomfortable combination of heat and humidity.
日本の夏の蒸し暑さには慣れない。
I can't get used to the humidity of Japanese summers.
The adjective meaning 'hot and humid', 'muggy'. This is the most natural way to describe the weather when it feels sticky.
An onomatopoeic adverb/adjective describing a damp, humid, and often unpleasant feeling. Can refer to weather or a damp room.
Another onomatopoeia for mugginess, similar to 蒸し暑い but more colloquial and sensory.
Referring to moisture content in things like soil, walls, or the air, often with a negative connotation of dampness.
Means 'moisture' or 'water content'. Used for moisture in food, soil, skin, etc., not specifically for atmospheric humidity.
この土は水分が多い。
This soil has a lot of moisture.
A slightly literary or descriptive word for 'dampness' or 'moisture'. Often used for a pleasant or slight moisture.
湿度 (しつど) is the objective, measurable humidity. 蒸し暑さ (むしあつさ) is the subjective feeling of mugginess. Use 湿度 when talking about percentages or weather data, and 蒸し暑い/蒸し暑さ when complaining about the weather.
湿度は60%ですが、蒸し暑く感じます。
The humidity is 60%, but it feels muggy.
English speakers often say 'the humidity is terrible'. In Japanese, it's more natural to use an adjective like 蒸し暑い (むしあつい) or an onomatopoeia like ジメジメ (じめじめ) rather than always using the noun 湿度 (しつど).
この蒸し暑さは嫌だ。
I hate this humidity.
湿気で髪が広がる。
The humidity makes my hair frizzy.
今日は蒸し暑いね。
It's so humid today, isn't it?
蒸し暑くて寝られない。
It's so humid I can't sleep.
梅雨で毎日ジメジメしている。
It's humid and damp every day because of the rainy season.
外はムシムシしてるよ。
It's really muggy outside.
空気に湿り気がある。
There's moisture in the air.