In which units is prevailing visibility reported?

Prevailing visibility is primarily reported using statute miles and fragments. Statute miles are the standard unit for reporting visibility distances in the United States, aligning with meteorological guidelines that emphasize clarity and consistency in observations. When visibility is less than a full statute mile, it is commonly reported in fractions or fragments of a mile to provide a more precise understanding of the visibility conditions.

For example, if the visibility is reported as "3/4 mile," it gives a clearer depiction of how far one can see compared to simply stating "0.75 miles." This method also facilitates communication during critical weather observations, ensuring that essential information is conveyed effectively to pilots, meteorologists, and other stakeholders.

While other units like kilometers can offer useful information, particularly in regions that utilize the metric system, they are not the standard for prevailing visibility in the context of this question. Therefore, the option that includes both statute miles and fragments captures the most widely accepted practice for reporting visibility in surface weather observations.