Definition
A reported ceiling condition in which no cloud layer reported as broken or overcast exists below 12,000 feet, and the sky is sufficiently clear that no ceiling value is assigned. In weather reports, this is indicated by the absence of a ceiling and is sometimes described as 'sky clear' or 'unlimited.'
Plain English
There is no cloud layer low enough to count as a ceiling, so the sky overhead is effectively wide open.
Context Anchor
Seen in aviation weather reports and forecasts when judging whether clouds will limit takeoff, landing, or visual flight.
Derivation
Ceiling comes from the idea of an overhead limit, like the ceiling of a room. Unlimited means no such overhead limit is being reported; in this aviation weather use, there is no reported cloud layer acting as the ceiling.
Why Pilots Care
Confirms visual flight rules remain available without cloud restrictions, simplifying route and altitude planning.
Intuition Check
Unlimited does not mean the weather is perfect or that the sky is empty. It means the report has no cloud layer or vertical-visibility limit that counts as a ceiling.
Example Sentence 1
The morning briefing reported an unlimited ceiling, so the cross-country could be flown at any practical VFR altitude.
Example Sentence 2
With an unlimited ceiling reported at the destination, we expected clear conditions for the approach.