Cirrus Clouds

Cirrus clouds are thin, feathery clouds high in the sky. They look like white streaks or curls. The name cirrus comes from a word that means curl of hair. These clouds are made of tiny ice crystals, not water drops. They form very high up where the air is cold.

How They Form

Cirrus clouds form more than 20,000 feet up in the sky. At that height, the air is so cold that water freezes into ice. Strong winds blow the ice crystals into long, thin shapes. The wind is why these clouds look stretched out and wispy. They move fast across the sky but can be hard to see moving because they are so high up.

What They Tell Us

Cirrus clouds often show up when the weather is about to change. If you see them, a storm or rain might be coming in a day or two. But on their own, cirrus clouds do not bring rain or snow. They are often the first clouds to show up in a clear blue sky. People have watched them for thousands of years to guess the weather.

Fun Facts

• Cirrus clouds can be more than 5 miles above the ground.
• The ice crystals in cirrus clouds can make rainbows around the sun.
• Cirrus clouds sometimes make lines in the sky called mare's tails.

Did You Know?

The white trails left behind jet airplanes are actually a kind of cirrus cloud made from the plane's exhaust.