Definition
The height above the ground or water of the lowest layer of clouds or obscuring phenomena that is reported as 'broken,' 'overcast,' or 'obscuration,' and not classified as 'thin' or 'partial.'
Plain English
The height above the ground of the lowest cloud layer that covers more than half the sky. If the cloud cover is only scattered or thin, it doesn't count as a ceiling.
Context Anchor
Pilots encounter ceiling in airport weather reports, forecasts, preflight weather briefings, and decisions about whether the weather is good enough for visual flying.
Derivation
From the everyday meaning of 'ceiling' as the upper surface of a room. In aviation, the sky becomes the 'room' and the cloud layer is its ceiling — the lid above the pilot.
Why Pilots Care
Determines whether VFR flight is possible and sets the minimums for takeoff, landing, and alternate airport planning.
Analogy
Think of standing in a room: the ceiling limits how much clear space you have above you. In weather, the ceiling is the cloud or sky blockage that limits the clear air above the ground.
Grounding Statement
If low clouds cover most of the sky above an airport, the reported ceiling tells the pilot how much clear vertical space exists below those clouds.
Intuition Check
Ceiling does not mean the top of a cloud layer. It means the height of the lowest mostly covering cloud layer or sky blockage above the ground.
Example Sentence 1
The ATIS reported a ceiling of 1,200 feet broken, so the pilot filed IFR rather than attempting the trip VFR.
Example Sentence 2
Low ceilings at the destination forced the pilot to request an IFR clearance.