Translation guide
In Japanese, Celsius is expressed as 摂氏 (せっし) or more commonly just 度 (ど) after the number. The word セルシウス (セルシウス) is also understood but less common.
25 degrees Celsius
Celsius scale
Referring to the Celsius temperature scale in general or as a unit.
Formal term for Celsius, often used in written or technical contexts. Can be combined with () as (), but alone is sufficient.
Water boils at 100 degrees Celsius.
The most common way to say 'degrees Celsius' in everyday conversation. Simply attach 度 to the number. Context usually makes it clear it's Celsius.
Today's temperature is 25 degrees (Celsius).
Katakana rendering of 'Celsius'. Recognized but less natural than 度 or 摂氏. May be used in some product names or when emphasizing the scale.
This thermometer supports both Celsius and Fahrenheit.
In daily conversation, Japanese people almost always use 度 (ど) after the number to express temperature in Celsius. There is no need to explicitly say 'Celsius' unless contrasting with Fahrenheit.
It seems it will exceed 30 degrees tomorrow.