Definition
A ceiling height assigned by a weather observer when the actual height of the cloud base cannot be measured directly with a ceilometer or other instrument, but is judged from available evidence such as pilot reports, balloon observations, terrain features, or visual estimation.
Plain English
A best-guess height of the cloud base above the ground, used when there is no instrument reading available. The observer works it out from clues rather than measuring it directly.
Context Anchor
Seen in airport weather reports and weather-observation discussions when judging whether cloud height will affect a takeoff, landing, or local flight.
Derivation
‘Ceiling’ borrows the everyday idea of the inside top of a room — the lowest overhead surface. Applied to weather, it means the lowest layer of cloud that covers most of the sky, treated as the ‘roof’ above the aircraft. ‘Estimated’ flags that the height was judged rather than measured.
Why Pilots Care
Pilots use the reported ceiling height to decide whether visual or instrument flight rules apply and to plan safe altitudes for takeoff, en route, and approach segments.
Intuition Check
Estimated does not mean a casual guess; it means an approved estimate made when a direct measurement is not available. Ceiling does not mean the top of the clouds; it means the lowest mostly covering cloud layer above the reporting point.
Example Sentence 1
The METAR showed an estimated ceiling of 1,500 feet, so the pilot built in extra margin before committing to the approach.
Example Sentence 2
With an estimated ceiling at 800 feet the pilot elected to remain on the ground rather than attempt a VFR departure.