Overcast describes a sky completely covered with clouds, blocking out the sun. On an overcast day, you won't see blue sky or sunshine, just a blanket of gray clouds stretching from horizon to horizon. The light feels flat and shadowless, like someone dimmed the brightness of the whole world.

Overcast weather happens when a thick layer of clouds moves in and settles overhead. Unlike partly cloudy days where patches of blue peek through, an overcast sky is uniformly gray. It might look gloomy, but overcast doesn't necessarily mean rain is coming. Many overcast days stay dry, though the heavy cloud cover often makes the air feel damp and cool.

Meteorologists use overcast as a precise term meaning at least 90% of the sky is covered by clouds. Photographers sometimes prefer overcast conditions because the diffused light eliminates harsh shadows and makes colors look rich and even. Pilots pay attention to overcast skies because thick cloud cover affects visibility and flight conditions.

People also use overcast metaphorically to describe moods or atmospheres that feel heavy or subdued, like when someone says an overcast feeling hung over the disappointed team after their loss.