A temperature scale in which the fixed points are at the temperatures at standard pressure of ice in equilibrium with water (0°C)) and water in equilibrium with steam (100 °C). The scale between these two temperatures, is divided in 100 degrees. The degree Celsius (°C) is equal in magnitude to the kelvin.

The scale was named after the Swedish astronomer Anders Celsius (1701-44), who devised the inverted form of this scale in 1742.

This scale was formerly known as the centigrade scale, the name was officially changed in 1948 to avoid confusion with a hundredth part of a grade.