Flying through clouds

The window suddenly turns white and the aircraft wobbles a little. You're in a cloud; a few minutes later you often come out into sunshine.

What is a cloud?

A cloud is billions of tiny water droplets or ice crystals hanging in the air. Flying through one is like moving through thick fog.

Why the light bumps?

Clouds form where air rises and sinks. Inside puffy, cotton-like (cumulus) clouds especially, the air moves gently up and down, and the aircraft passes that on as short bumps. Flat, layered clouds are usually calmer.

What do pilots do?

Pilots see cloud density on weather radar. They fly through light clouds and go around dense, tall storm clouds.

Above the clouds

After takeoff, once you clear the cloud layer, you see sunshine and a white sea from the window, and the air often calms down. On landing it's the reverse: you enter the cloud layer in the last minutes and stay in the white for a short while. Both are among the most ordinary moments of a flight.