A stratocumulus cloud belongs to a class of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumuli, and the whole being at a lower altitude, usually below 2,400 m (8,000 ft). Weak convective currents create shallow cloud layers because of drier, stable air above preventing continued vertical development.

Vast areas of subtropical and polar oceans are covered with massive sheets of stratocumuli. These may organize into distinctive patterns which are currently under active study. In subtropics, they cover the edges of the horse latitude climatological highs, and reduce the amount of solar energy absorbed in the ocean. When these drift over land the summer heat or winter cold is reduced. 'Dull weather' is a common expression incorporated with overcast stratocumulus days, which usually occur either in a warm sector between a warm and cold front in a depression, or in an area of high pressure, in the latter case, sometimes persisting over a specific area for several days. If the air over land is moist and hot enough, stratocumuli may develop to various cumulus clouds, or, more commonly, the sheet of stratocumulus may become thick enough to produce some light rain. On drier areas they quickly dissipate over land, resembling cumulus humilis. This often occurs in late morning in areas under anticyclonic weather, the stratocumulus breaking up under the Sun's heat and often reforming again by evening as the heat of the Sun decreases again.