CAVOK

"Clouds and visibility are OK" refers to weather that meets the following conditions:

• Visibility 10 km and more,
• There are no clouds of the Cumulonimbus or Cumulus type above the airport,
• There is no cloud above the airport below 5000 ft (1500m) or the highest minimum sector altitude (whichever is higher),
• There are no significant weather phenomena (rainfall, thunderstorms, fog, etc.) occurring or expected according to the forecast.