Prevailing visibility is reported in:

Prevailing visibility is reported in statute miles and fractions because this measurement is standard in aviation and meteorology in the United States. Statute miles are commonly understood by pilots and other aviation personnel as they calibrate their navigational and operational decisions.

The use of fractions allows for more precise communication of visibility conditions, which is critical for flight operations. For instance, visibility might be reported as 1.5 statute miles, conveying that visibility extends one and a half miles. This format ensures that pilots have a clear understanding of visibility conditions, which can directly impact their flight safety and decision-making processes.

In contrast, nautical miles are primarily used for maritime and aeronautical navigation over water, and kilometers are used more commonly outside of the United States or within specific applications not primarily dictated by aviation operations in the U.S. Lastly, reporting visibility in hundreds of feet is not standard; while ceilings and elevations are often measured in this way, prevailing visibility specifically adheres to statute miles.