Definition
Weather conditions in which flight by outside visual reference is permitted, meaning visibility, distance from clouds, and ceiling meet or exceed the minimums established in 14 CFR Part 91 for visual flight rules (VFR) operations. The specific values vary by airspace class and altitude.
Plain English
Weather that is good enough to fly by looking outside the airplane — clear enough air, far enough from clouds, and a high enough cloud base to legally fly without relying on instruments.
Context Anchor
You will see VMC discussed in departure procedures, instrument training, flight planning, and weather decisions when deciding whether the pilot can use outside visual references or must rely mainly on instruments.
Derivation
‘Meteorological’ comes from the Greek meteoron, meaning ‘things in the sky.’ So visual meteorological conditions literally means ‘sky conditions good enough to see by.’ That is exactly what the term refers to operationally.
Why Pilots Care
Determines whether visual flight rules apply, affecting whether the pilot needs an instrument rating and how the flight is conducted.
Intuition Check
Do not read VMC as simply “nice weather.” In aviation, VMC means the weather meets specific visibility and cloud-clearance requirements for the place and type of flight.
Example Sentence 1
The pilot checked the weather and confirmed VMC existed along the entire route, so the flight could be conducted under VFR.
Example Sentence 2
When visual meteorological conditions exist at the destination, the flight can be completed under visual flight rules.