What does "CAVOK" mean in a METAR report?

In a METAR report, "CAVOK" stands for "Ceiling and Visibility OK." This term is used to indicate that the weather conditions at the reporting station are satisfactory, meaning there are no significant weather phenomena affecting visibility. Specifically, it implies that there is no significant cloud below 5,000 feet above the ground or within 1,000 feet of the airport elevation and that visibility is at least 10 kilometers (or 6 statute miles). Additionally, there are no significant weather events, such as precipitation or fog, that would otherwise affect aviation operations.

Understanding "CAVOK" is important for pilots and air traffic controllers, as it simplifies the interpretation of weather conditions. When CAVOK is reported, it conveys a clear picture that flying conditions are suitable, allowing for smoother operations. Other choices do not accurately describe the specific aviation-related meaning of "CAVOK," which focuses on both ceiling and visibility being adequate for safe flight operations.