What does "CAVOK" signify in a METAR report?

"CAVOK" stands for "Ceiling And Visibility OK." This term is used in METAR reports to indicate that visibility is good and there are no significant weather phenomena affecting the area, meaning that there are no clouds below the minimum threshold for reporting or any obstructions to visibility. Specifically, it implies that the visibility is 10 kilometers or more, and there are no clouds below 5,000 feet or below the highest minimum for that airport, whichever is greater.

The choice of "Ceiling and visibility okay" accurately conveys the essence of the CAVOK condition. It simplifies reporting by informing pilots and air traffic controllers that all visual flight rules (VFR) conditions are met without additional details about specific cloud types or other visibility obstructions.

The other options, while they contain relevant terms related to aviation weather reporting, do not capture the precise meaning of CAVOK. They might confuse the intended meaning of good visibility and acceptable cloud conditions, which is why they do not represent the definition accurately.