Cirrus — Ice in the Sky
Cirrus clouds are the highest common clouds, floating 20,000 to 40,000 feet above the ground — so high that the air is far below freezing! Because of this extreme cold, cirrus clouds are not made of water droplets like other clouds. They are made entirely of tiny ice crystals.
Cirrus clouds look like thin, wispy streaks or curls painted across the sky with a delicate brush. The word 'cirrus' means 'curl of hair' in Latin, and that is exactly what they look like — thin strands of white hair stretched across the blue sky.
The wispy shape comes from strong high-altitude winds (called jet streams) that blow the ice crystals sideways, stretching them into long trails. Sometimes cirrus clouds look like horse tails blowing in the wind.
Cirrus clouds usually mean fair weather RIGHT NOW, but they can be a sign that weather will change in the next day or two. When cirrus clouds gradually thicken and spread across the sky, a warm front (and rain) is often on its way.
Sunsets are especially beautiful when cirrus clouds are present. The thin ice crystals catch the last rays of the setting sun, creating spectacular streaks of orange, pink, and red across the sky.
**Cloud Spotter Tip:** Cirrus clouds are so high that commercial airplanes fly at the same altitude! When you see a jet trail (contrail) in the sky, it forms at the same height as cirrus clouds.