What is Celcius?

Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). The degree Celsius can refer to a specific temperature on the Celsius scale as well as serve as unit increment to indicate a temperature interval (a difference between two temperatures or an uncertainty). “Celsius” is named after the Swedish astronomer Anders Celsius (1701 – 1744), who developed a similar temperature scale two years before his death.