Definition
A paired weather reference describing the two atmospheric conditions that most directly determine whether a flight can be conducted under visual flight rules: visibility, the horizontal distance at which prominent objects can be seen and identified, and ceiling, the height above the ground or water of the lowest layer of clouds reported as broken or overcast (or the vertical visibility into an obscuration). In flight planning and scenario-based training, visibility/ceiling is treated as a single decision input because the two values together define how much room a pilot has to see and avoid terrain, traffic, and weather.
Plain English
How far you can see ahead, and how low the cloud layer is above you. These two numbers are usually considered together because they decide whether the weather is good enough to fly visually.
Context Anchor
Seen in weather reports, preflight planning, instructor scenarios, and go/no-go decisions before and during a flight.
Derivation
Visibility comes from the Latin visibilis, meaning 'able to be seen.' Ceiling comes from the Latin caelum, meaning 'sky' or 'heavens,' and entered English as the inside overhead of a room — the upper limit of the space you occupy. In aviation it kept that same idea: the cloud layer acts as the overhead 'lid' on the airspace a VFR pilot can use.
Why Pilots Care
These values determine whether VFR flight is legal and safe or if IFR procedures and higher minimum altitudes are required.
Grounding Statement
If you cannot see far enough ahead, or the clouds are too low above you, the flight may no longer have the visual space needed for safe operation.
Intuition Check
Do not read visibility/ceiling as a general comment that the weather is “good” or “bad.” Visibility is the seeing distance, and ceiling is the height of the lowest significant cloud cover above the ground—not the top of the clouds.
Example Sentence 1
During the preflight briefing, the instructor asked the student to evaluate the visibility/ceiling along the route and decide whether the flight could be completed under VFR.
Example Sentence 2
With visibility dropping to two miles and a ceiling at eight hundred feet, the instructor canceled the VFR training flight.