Aviation glossary

What is CAVOK?

Ceiling And Visibility OK

CAVOK means visibility is 10 km or more, there is no significant cloud below 5,000 ft, and no significant weather: in short, excellent flying conditions.

CAVOK (pronounced "cav-oh-kay", from "Ceiling And Visibility OK") is a shorthand used in a METAR or TAF when three conditions are all met: visibility is 10 km or more; there is no cloud below 5,000 ft (or below the highest minimum sector altitude, whichever is greater) and no cumulonimbus or towering cumulus at any level; and there is no significant weather such as rain, fog or thunderstorms.

When all of that is true, the report simply says CAVOK in place of the separate visibility, cloud and weather groups. It is one of the most welcome words a VFR pilot can read.

Worth noting: "Cavok" is also the name of a legacy flying-school booking system. The aviation term came first; the software borrowed it.

flyWilco vs Cavok the booking software →

Related terms

METARA METAR is a routine observation of the actual weather currently reported at an aerodrome.TAFA TAF is a forecast of the expected weather at an aerodrome over a set period, usually 9, 24 or 30 hours.VFRVFR (Visual Flight Rules) is flying by visual reference to the ground and horizon, in weather at or above the visual minima.Flight category (VFR, MVFR, IFR, LIFR)Flight category is a colour-coded summary of conditions (VFR, MVFR, IFR or LIFR) derived from the cloud ceiling and visibility.

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