What type of weather phenomena does "fog" typically refer to in aviation terminology?

In aviation terminology, "fog" is specifically defined as a weather phenomenon that significantly reduces visibility. When visibility is less than 1 mile, it is classified as fog. This reduced visibility can create hazardous flying conditions, particularly during takeoff and landing, as pilots rely heavily on visual references.

The other options represent different weather phenomena that do not pertain to the specific definition of fog in aviation. Cumulus cloud formations refer to a type of cloud associated with fair weather rather than poor visibility. Freezing precipitation describes weather where rain turns into ice upon contact with surfaces, affecting runway conditions but not visibility directly. Strong winds, while they can impact flight safety, particularly during approach or landing, do not relate to the definition of fog or its visibility criteria. Therefore, the key aspect of fog in aviation remains its significant impact on visibility.