Stratus clouds form in calm, stable conditions when gentle breezes raise cool, moist air over colder land or ocean surfaces. These clouds can exist in a variety of thicknesses and are sometimes opaque enough to darken days, allowing for little light to pass through.

At what altitude do stratus clouds form?

Stratus. Usually forms between the surface and 2,000ft, but cloud base can be up to 4,000ft. Thick stratus can produce considerable precipitation, particularly in hilly or coastal regions, though in some cases this precipitation may be falling from higher clouds such as nimbostratus.

What season do stratus clouds form?

Usually stratus clouds and fog form when it has been cold out and then warmer, wet air blows in. As the warm air flows over the cold ground or over the cold air near the ground, the water vapor in the warm air condenses into drops of water that make a cloud.