Facts about the Celsius, Fahrenheit and Kelvin scales

The degree Celsius (°C) was known until 1948 as centigrade.
The unit is named after the Swedish astronomer Anders Celsius (1701–1744).
From 1744 until 1954, 0 °C was defined as the freezing point of water and 100 °C was defined as the boiling point of water.
Throughout the world, except in the US and a few other countries, the Celsius temperature scale is used for practically all purposes.
Fahrenheit (°F) is the temperature scale named after the physicist Daniel Gabriel Fahrenheit (1686–1736).
A temperature interval of 1 Fahrenheit degree is equal to an interval of 5⁄9 degrees Celsius.
−40 °C and −40 °F represent the same temperature.
The Fahrenheit scale is still used in the United States, Liberia, Palau, Jamaica, and Belize for everyday applications.
The Kelvin scale is named after the physicist and engineer William Thomson, 1st Baron Kelvin (1824–1907).
The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
The kelvin (symbol K) is the primary unit of measurement in the physical sciences.
The kelvin is often used in the measure of the color temperature of light sources.

Some key scale relations - Kelvin - Celsius - Fahrenheit

Facts About All