Five interesting facts about fog
What is it exactly?
Fog can be simply defined as a cloud touching the ground.
High humidity causes it
Fog generally forms when the relative humidity reaches 100 percent at ground level.
Cloudy California town
The foggiest area in the United States is Point Reyes, Calif. It is in the top two foggiest land areas in the world with more than 200 days of fog per year.
There is variety
There are many types: radiation fog, sea fog, ground fog, advection fog, steam fog (also called evaporation fog), precipitation fog, upslope fog, valley fog, ice fog, freezing fog and artificial fog.
Sun a fog foe
Fog evaporates after sunrise as the sun warms the fog from the top down. The thicker the fog, the longer it takes to dissipate.