How Are Clouds Classified?

There are many different types of clouds, each with an unique shape and location in the sky.
Credit: UCAR

Clouds are given different names based on their shape and their height in the sky. Some clouds are puffy like cotton while others are grey and uniform. Some clouds are near the ground, while others are near the top of the troposphere. The diagram on the right shows where different types of clouds are located in the sky.

How Are Clouds Classified?

Most clouds can be divided into groups (high/middle/low) based on the height of the cloud’s base above the Earth’s surface. Other clouds are grouped not by their height, but by their unique characteristics, such as forming alongside mountains (Lenticular clouds) or forming beneath existing clouds (Mammatus clouds).

The table below provides information about cloud groups and any cloud types associated with them. Click on the cloud images in the table to learn more about each cloud type.

Cloud Group and Height * Cloud Types

High Clouds

5 – 13 km (16,000 – 43,000 ft)

Noctilucent clouds are the highest clouds in the sky, however they are not associated with weather like the rest of the clouds in this table.

Cirrus clouds Cirrocumulus clouds Cirrostratus clouds

Middle Clouds

2 – 7 km (7,000 – 23,000 ft)

Altocumulus clouds Altostratus clouds

Low Clouds

Surface – 2 km (surface – 7,000 ft)

Stratus clouds Stratocumulus clouds Nimbostratus clouds

Clouds with Vertical Growth

Surface – 13 km (surface – 43,000 ft)

Clouds that grow up instead of spreading out across the sky.

Cumulus clouds Cumulonimbus clouds

Unusual Clouds

Clouds that form in unique ways and are not grouped by height.

Lenticular clouds Kelvin-Helmholtz clouds Mammatus clouds


5 – 13 km (16,000 – 43, 000 ft)


* The cloud heights provided in this table are for the mid-latitudes. Cloud heights are different at the tropics and in the polar regions. In addition, a few other cloud types are found in higher layers of the atmosphere. Polar stratospheric clouds are located in a layer of the atmosphere called the stratosphere. Polar mesospheric clouds, which are also called noctilucent clouds, are located in the atmospheric layer called the mesosphere.