By observing clouds, you can often predict the incoming weather. Clouds are classified by their altitude (height in the sky) and their shape.
Some clouds are as high as a jet; others are near the ground. Some are white puffs and some are grey and lumpy.
Overall, there are three different types of clouds: high, middle, and low.
Bases start above 20,000 feet, on average
Cirrus: Thin, featherlike, crystal clouds.
Cirrocumulus: Thin clouds that appear as small “cotton patches.”
Cirrostratus: Thin white clouds that resemble veils.
Bases start at between 6,500 and 20,000 feet
Altocumulus: Gray or white layer or patches of solid clouds with rounded shapes.
Altostratus: Grayish or bluish layer of clouds that can obscure the Sun.
Bases start below 6,500 feet
Stratus: Thin, gray, sheetlike clouds with low bases; may bring drizzle or snow.
Stratocumulus: Rounded cloud masses that form in a layer.
Nimbostratus: Dark, gray, shapeless cloud layers containing rain, snow, or ice pellets.
Clouds With Vertical Development
Form at almost any altitude and can reach to more than 39,000 feet
Cumulus: Fair-weather clouds with flat bases and dome-shape tops.
Cumulonimbus: Large, dark, vertical clouds with bulging tops that bring showers, thunder, and lightning.
Cloud Types and Pronunciation
One of our readers asked a good question: How do you pronounce these cloud names? See the chart below for a reference.
If you enjoy cloud-watching, have some fun with our “Cloud Shapes: What do you see?” pages.