How does fog reduce visibility?

Fog significantly reduces visibility primarily because it consists of tiny water droplets suspended in the air, which scatter and diffuse light. This scattering effect creates a condition where objects become less distinguishable at distances greater than the fog's thickness.

Visibility is considered reduced when it falls below 5/8 statute miles, which is the threshold defined for fog. In aviation terms, visibility is crucial for safe navigation and operations. When visibility dips below this level, it poses a higher risk to pilots during takeoff, landing, and taxiing, as they rely on clear views of both the runway and surrounding areas.

Understanding this threshold allows pilots, meteorologists, and air traffic control to assess conditions and implement appropriate safety measures, such as delays or diversions, in order to ensure flight safety during foggy conditions.