<P> The Celsius scale , previously known as the centigrade scale , is a temperature scale used by the International System of Units ( SI ) . As an SI derived unit , it is used by all countries in the world , except the United States , Myanmar , and Liberia . It is named after the Swedish astronomer Anders Celsius ( 1701 -- 1744 ) , who developed a similar temperature scale . The degree Celsius ( symbol : ° C ) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval , a difference between two temperatures or an uncertainty . Before being renamed to honor Anders Celsius in 1948 , the unit was called centigrade , from the Latin centum , which means 100 , and gradus , which means steps . </P>
what is the origin of the word celsius
named after the Swedish astronomer Anders Celsius