What is the characteristic of cloud ceilings in aviation?

The characteristic of cloud ceilings in aviation specifically refers to the height of the lowest layer of clouds that is present. A broken or overcast cloud cover indicates a ceiling because these conditions affect flight operations, particularly during takeoff and landing.

When the sky is broken, it means that clouds cover more than 5% but less than 100% of the sky, while overcast indicates that clouds cover 100% of the sky. Both scenarios define a cloud ceiling that pilots need to factor into their approach and navigation choices. In aviation, ceilings are crucial for determining if visual flight rules (VFR) or instrument flight rules (IFR) apply, affecting how pilots navigate.

In contrast, scattered clouds only imply that there are some clouds but not in significant enough concentration to create a ceiling that impacts visibility or flight operations. Clear skies, defined by a lack of significant cloud cover, indicate no ceiling at all, which generally allows for more flexible flight operations. Visibility over clouds, while important for overall situational awareness, does not classify as a characteristic of a ceiling since it pertains more to the conditions above the clouds rather than the height of the cloud layer itself.