Which temperature scale defines the freezing point of water at 0°?

The Celsius temperature scale is defined in such a way that the freezing point of water is established at 0°. This scale is widely used in most of the world for everyday temperature measurements, particularly in scientific contexts. The Celsius scale is based on the properties of water, with 0° marking the phase transition from liquid to solid under standard atmospheric conditions.

In contrast, other temperature scales have different reference points. For example, the Kelvin scale places absolute zero at 0 K and defines the freezing point of water as 273.15 K, while the Fahrenheit scale indicates the freezing point of water at 32° F. The Rankine scale, similar to Kelvin but based on the Fahrenheit degree, marks the freezing point of water at 491.67° R. Understanding these different scales helps clarify why Celsius is unique in defining the freezing point of water at 0°.