Definition
A temperature scale, also called Celsius, on which the freezing point of pure water at standard sea-level pressure is 0 degrees and the boiling point is 100 degrees. The interval between these two reference points is divided into 100 equal degrees.
Plain English
A way of measuring temperature where water freezes at 0 degrees and boils at 100 degrees, with the space between divided into 100 equal steps.
Context Anchor
Seen in aviation weather, aircraft manuals, maintenance information, and performance charts that list temperature in degrees C.
Derivation
From Latin centum (hundred) and gradus (step or degree). The name reflects the 100 equal steps between water freezing and water boiling. The scale is also called Celsius after the Swedish astronomer Anders Celsius, who proposed the 100-point scale in 1742.
Why Pilots Care
Pilots use Centigrade (Celsius) temperatures for density altitude computations, engine performance limits, and interpreting METARs and TAFs.
Intuition Check
Centigrade is not a separate aviation temperature scale from Celsius. It is the older name for Celsius.
Example Sentence 1
The METAR reported the surface temperature as 28 degrees Centigrade, which raised the density altitude well above the field elevation.
Example Sentence 2
The pilot checked the Centigrade temperature before deciding whether de-icing was needed.