Main types of fog, radiation fog

There are four main types of fog: radiation fog, advection fog, frontal fog and sea smoke.
Radiation fog is formed in a clear sky and adjacent to rapidly cooling land.
The land will cool the air above it, causing water vapor to condense into droplets.
Radiation fog first forms in valleys, and during the early morning it can even expand several miles out to sea. Rivers and estuaries may also be affected.
When the sun rises and the land starts to heat up, radiation fog quickly disperses.
In situations where the land takes longer to heat up, for example, when it is overcast, radiation fog may persist.