During variable visibility conditions, what is the reportable prevailing visibility for 5/8, 3/4, and 7/8 statute miles?

In the context of aviation weather reporting, prevailing visibility is defined as the greatest horizontal distance at which objects can be seen from a specific location. When visibility is variable, particularly in conditions where measurements might fall between standard reporting values, certain rules apply.

For the reported visibility values you provided, if you are considering values like 5/8, 3/4, and 7/8 statute miles, the prevailing visibility must be rounded to the nearest standard reporting value. The standard visibility values that are often used in aviation reports are 1/4 mile increments up to 1 statute mile and whole miles thereafter.

In this case, for the variable visibility of 5/8 statute miles, it rounds down to 3/4 statute miles as it’s closer to that value than to 1 statute mile. The segregated values themselves suggest a trend towards 3/4 statute miles being the prevailing visibility during those conditions. Therefore, 3/4 statute miles is the correct reported value, as it accurately reflects the noted visibility while adhering to aviation reporting standards.