1.
water temperature (of a body of water, an aquarium, a hot bath, an engine cooling system, etc.)
The temperature of water in any context — the sea, rivers, swimming pools, fish tanks, hot baths, kettles, or the cooling systems of cars and machinery. 水温 is a neutral, technical-flavored term used wherever water temperature needs to be specified.
水温を測る。
To measure the water temperature.
今日は海の水温が低い。
The sea temperature is low today.
熱帯魚を飼うには水温を二十六度前後に保つ必要がある。
When keeping tropical fish, you need to maintain the water temperature at around 26 degrees.
近年の海面水温の上昇は、気候変動の影響を示す重要な指標とされている。
The recent rise in sea-surface water temperatures is regarded as an important indicator of the effects of climate change.
水温 simply means "water temperature" — the temperature of water in any context.
FORMATION:
- 水 ("water") + 温 (from 温度 "temperature") → 水温
TYPICAL DOMAINS:
- Marine and freshwater science (海の水温, 湖の水温)
- Aquarium hobby and fish farming
- Swimming and diving (pool and ocean temperatures)
- Hot baths and onsen (spring water temperatures)
- Automotive (水温計: engine coolant-temperature gauge)
- Industrial and chemical processes
COMMON COLLOCATIONS:
- 水温が上がる / 下がる: water temperature rises / falls
- 水温を測る: to measure water temperature
- 水温を保つ: to maintain a water temperature
- 水温計: water-temperature gauge / thermometer
- 海面水温: sea-surface temperature (a key meteorological / climate term)
- 適正水温: optimal water temperature
SIMILAR / RELATED TERMS:
- 気温: air temperature — the parallel word for ambient air
- 体温: body temperature
- 室温: room temperature
- 温度: temperature (general) — the umbrella term; 水温 = 水の温度
- 湯温: hot-water temperature — a closely related word focused on heated water (baths, kettles, hot springs); often more natural than 水温 when the water is intentionally hot
- 海水温: sea-water temperature — a more specific compound, common in marine science and weather news
USAGE NOTES:
- For an extremely hot bath or kettle, 湯温 is more idiomatic than 水温: お風呂の湯温は四十二度です ("the bath temperature is 42 degrees").
- 水温 is preferred when the water in question is naturally cool, when the temperature could be high or low, or when it is being measured/controlled in a technical setting.