Temperature is not a quantity in the strict sense of the term as the majority of other measurement units are. A quantity is something which can be increased or decreased, for example length, area, power output, etc.

Measuring a quantity G (of whatever nature) means comparing it to another quantity U of the same nature, chosen as the unit. The result of the measurement is a whole number (for example 5) if the unit U is contained a whole number of times in the quantity G in question (5 times in this case). A quantity is directly measurable if we can define the relationship or the equality or the sum of two values of such quantity. Length and area are measurable quantities.

On the other hand, a temperature referenced using the Celsius temperature scale is not a measurable quantity; we can identify the equality of two temperatures but we cannot add them. You can therefore refer to: evaluating, comparing, marking or indicating temperatures but not measuring them in the correct sense of the term.