Stratus

What it looks like

A uniform grey layer with no texture worth speaking of, often low enough to hide hills, masts and tall buildings. When it reaches the ground it is fog. Drizzle or fine snow grains fall from it, never proper rain drops.

What it means

Stable, damp air and light winds. Inland in summer it often burns off by late morning; in winter, or near the coast, it can sit for days. It is the cloud of cancelled views and of very good soft light for photographs.

Not to be confused with

Nimbostratus, which is darker, thicker and gives steady rain, and altostratus, a higher sheet through which the sun shows like a blurred lamp behind frosted glass.