Plain English Meaning
A way of measuring how hot or cold something is, where 0 is the freezing point of water and 100 is the boiling point of water. Pilots use this scale almost everywhere temperature comes up in flying.
Full Definition
A temperature scale on which water freezes at 0° and boils at 100° at standard sea-level pressure. It is the standard temperature scale used in aviation worldwide, including in weather reports, performance charts, and altimeter setting calculations.
Context Anchor
Pilots see Celsius in weather information, aircraft manuals, performance charts, and training material when temperature is given.