Which measurement unit is used for determining cloud height in a METAR?

The measurement unit used for determining cloud height in a METAR is feet above ground level. This is important because cloud heights report how far the cloud base is from the ground, which is crucial for aviation and meteorological purposes. In METAR reports, heights are typically stated in feet, providing pilots and meteorologists with a clear understanding of cloud formation altitude relative to their operational environment.

For instance, if a METAR indicates cloud height as "2500", it means the cloud base is at 2500 feet above the surface. Using feet as the standard unit aligns with common aviation practices in different regions, particularly in the United States, where aviation altitudes are predominantly measured in feet.

While other units like meters or kilometers are useful in different contexts, the specific use of feet above ground level in METAR reports ensures consistency and clarity in aviation communication, which is essential for flight safety and planning.