What is "fog"?

Fog is defined as a cloud that forms at or near the Earth's surface, which significantly reduces visibility. It consists of tiny water droplets that are suspended in the air and typically forms under specific conditions, particularly when humidity is high and temperatures cool, leading to condensation from water vapor in the air. The presence of fog can greatly impact transportation and safety due to its ability to obscure vision, making it a crucial phenomenon to understand in weather forecasting and aviation.

While fog is indeed associated with moisture and visibility concerns, it differs from precipitation, which refers to any form of water, liquid or solid, that falls from the atmosphere to the ground, such as rain or snow. It also should not be confused with tropical cyclones, which are large weather systems characterized by strong winds and heavy rain. Additionally, fog is not categorized as a layer of air pollution; although it can sometimes combine with smog, fog itself is primarily a natural weather occurrence rather than a result of pollutants. Understanding these distinctions helps clarify the unique nature and significance of fog in meteorology.