Q:

What Causes Fog to Form?

A:

Quick Answer

Fog forms when water droplets condense to form fog close to the ground. The water droplets are formed when water vapor bonds with condensation nuclei. Water evaporation can occur from bodies of water, wind, precipitation and atmospheric heating.

Continue Reading
Related Videos

Full Answer

Weather conditions must be perfect for fog to form. The relative humidity must be near 100 percent. The air temperature and dew point temperature must be close to one another as well. As the air reaches 100 percent relative humidity and the dew point is saturated, the water vapor condenses to form fog.

There are several types of fog. Radiation fog and advection fog are the most common types of fog. Radiation fog develops in the evening with clear skies and soft winds. A thick, moist layer of air develops on the ground resulting in a dense layer of fog. Radiation fog commonly occurs in the California Central Valley. On the other hand, advection fog forms when warm, moist air moves over cool air. Advection fog is common in the San Francisco Bay Area.

Upslope fog, freezing fog, ice fog and evaporation fog are other types of fog identified by the National Weather Service.

Fog is common in Newfoundland, California, Ireland, Argentina, the Pacific Northwest, Chile and southern Europe.

Learn more about Rain

Related Questions

  • Q:

    How Does Rain Happen?

    A: Rain occurs through the process of coalescence, where a mass of water droplets gathers around cloud condensation nuclei to saturate the atmosphere and allo... Full Answer >
    Filed Under:
  • Q:

    What Is Rainfall?

    A: Rainfall is the result of water vapor condensing and precipitating, forming droplets that fall from clouds due to gravity. It is an important part of the w... Full Answer >
    Filed Under:
  • Q:

    How Is Rain Formed?

    A: Rain is the result of water droplets gathering together in clouds and gravity causing the water droplets to fall as rain. Warm air has more water droplets ... Full Answer >
    Filed Under:
  • Q:

    What Makes It Rain?

    A: Rain and other forms of precipitation occur when water accumulates in the clouds and falls to the ground. This occurs due to the water cycle, which continu... Full Answer >
    Filed Under:

Explore