Celsius (°C)
Definition: Celsius (symbol: °C) is a temperature scale in which 0 °C is defined as the freezing point of water and 100 °C as its boiling point, both at standard atmospheric pressure (101.325 kPa). It is part of the International System of Units (SI).
History/origin: The scale was proposed by Swedish astronomer Anders Celsius in 1742. His original scale was inverted: 0 was boiling and 100 was freezing. It was later reversed by Carl Linnaeus and others to match today's convention. The unit was officially named Celsius in 1948.
Current use: Celsius is used in most countries of the world for everyday temperature measurement: weather forecasts, cooking, medicine, and science. It is the standard temperature unit in all countries except the United States, which primarily uses Fahrenheit.
