A unit of measurement of temperature. Part of the SI system of measurement, the Kelvin (K) scale starts at absolute zero (-273.15). Each Kelvin degree is the same as a Celsius degree. As a result, 0ºC (freezing water) is equal to 273.15K, and 100ºC (boiling water) is equal to 373.15K. From British physicist and mathematician Lord William Thomas Kelvin (1824-1907). See
color temperature and
SI units.