Definition
A measure of the average kinetic energy of the molecules in a substance, expressed in degrees on a defined scale such as Fahrenheit, Celsius, Kelvin, or Rankine. In aviation, temperature is a primary variable affecting air density, engine performance, aircraft performance, weather behavior, and instrument readings.
Plain English
How hot or cold something is, measured on a scale. In flying, temperature matters because it changes how the air behaves and how the airplane and engine perform in it.
Context Anchor
Seen in weather reports, forecasts, cockpit gauges, performance planning, and engine monitoring.
Derivation
From the Latin temperatura, meaning 'a proper mixing or proportion.' The original sense was about balance -- the right blend of hot and cold -- which evolved into the modern meaning of measuring where something sits on that scale.
Why Pilots Care
Accurate temperature readings directly affect engine operation, performance calculations, icing avoidance, and prevention of overheating or undercooling.
Grounding Statement
If the reported outside air temperature is below freezing, moisture on the aircraft or runway may become ice even if the sky looks clear.
Intuition Check
Do not assume temperatures are only about comfort. In aviation, temperatures are measured values that can affect aircraft performance, weather risk, and equipment limits.
Example Sentence 1
Before departure, the pilot checked the outside air temperature to calculate density altitude and confirm the airplane could climb out safely.
Example Sentence 2
Higher than normal temperatures during climb prompted the pilot to reduce power and enrich the mixture.