Nimbostratus cloud facts for kids

Quick facts for kids Nimbostratus cloud
Nimbostratus with pannus
Abbreviation	Ns
Symbol
Genus	Nimbostratus (rain, layered)
Altitude	500–5,500 m (2,000–18,000 ft)
Appearance	Dark and featureless layer cloud full of water vapor; responsible for rain and snow
Precipitation	Yes: rain, ice pellets, or snow; sometimes virga

A nimbostratus cloud is a type of cloud that looks dark grey and covers a large area. These clouds often bring steady rain, snow, or a mix of both. They do not produce lightning or thunder.

Even though they often appear low in the sky, nimbostratus clouds usually start forming higher up. They then grow vertically, reaching both lower and higher parts of the atmosphere. They are known for bringing precipitation over a wide region.

The name "nimbostratus" comes from Latin. "Nimbo" means "rain-bearing cloud."

How Do Nimbostratus Clouds Look?

Nimbostratus clouds have a fuzzy, unclear bottom. This cloud base can be quite low, sometimes close to the ground. It can also be found higher up, between about 2,000 to 13,000 feet (600 to 4,000 meters) in the middle sky.

Even though these clouds look dark from below, they can sometimes appear to glow from the inside. You can find nimbostratus clouds all over the world. However, they are most common in the middle parts of the Earth, like where many countries in Europe and North America are located.

Where and How Do Nimbostratus Clouds Form?

Nimbostratus clouds often form along weather fronts. These are areas where different air masses meet. They appear when warm air slowly rises over cooler air, creating a warm front or occluded front.

Before nimbostratus clouds arrive, you might see higher clouds like cirrostratus and altostratus. Sometimes, an altostratus cloud will grow thicker and move lower, turning into a nimbostratus cloud.

Unlike cumulonimbus clouds, nimbostratus clouds usually do not cause thunderstorms. However, in rare cases, if the warm air is very hot and humid, small cumulonimbus clouds can form within the nimbostratus. These are sometimes called "embedded thunderstorms."

In eastern Australia, these "embedded thunderstorms" are more common. Nimbostratus clouds in this region can bring very heavy rainfall. For example, Sydney once received over 327.8 millimeters (12.9 inches) of rain in just 24 hours from nimbostratus clouds. A large part of this rain, 100 millimeters (3.9 inches), fell in only three hours. This happened in September 2025.

What Weather Do Nimbostratus Clouds Bring?

Nimbostratus clouds often look very plain and dark.

When you see nimbostratus clouds, it usually means a warm front or occluded front is coming. These clouds bring steady, moderate rain or snow. This is different from the short, heavy downpours that cumulonimbus clouds cause.

The rain or snow from nimbostratus clouds can last for many hours, sometimes even days. How long it lasts depends on how fast the weather system is moving. Sometimes, the rain or snow falls but evaporates before reaching the ground. This is called virga. After the nimbostratus clouds pass, you will often see stratus or stratocumulus clouds instead.

The Story Behind the Name: Nimbostratus

The way we name clouds today started a long time ago. In 1802, a scientist named Luke Howard studied clouds in France. He grouped clouds into three main types based on how they looked and formed:

• Cirriform: Wispy, high clouds.
• Cumuliform: Puffy, lumpy clouds.
• Stratiform: Flat, layered clouds.

Howard also created names for clouds that were a mix of these types. One of his names was "nimbus." This described a complex cloud that grew tall and brought a lot of rain or snow.

Later, in the 20th century, scientists refined these cloud names. The "nimbus" cloud was reclassified as a type of layered cloud. It was then given the name nimbostratus. This new name was officially published in 1932 in the International Atlas of Clouds. This change helped make cloud classification clearer for everyone.

Different Types and Features of Nimbostratus

Nimbostratus clouds are usually very thick and uniform. Because of this, they don't have many different "species" or "varieties" like some other clouds.

However, they do have some special features:

• Precipitation: Nimbostratus clouds are known for bringing rain or snow. Sometimes, this precipitation can be very heavy because the cloud is so deep.
• Virga: As mentioned before, sometimes the rain or snow falls but evaporates before reaching the ground.
• Pannus: You might see small, ragged clouds forming below a nimbostratus cloud during rain. These are called "pannus" clouds. They look like torn pieces of cloud.
• How they form: Nimbostratus clouds can develop from other cloud types. For example, they can grow from cumulus or cumulonimbus clouds. They can also form when altocumulus, altostratus, or stratocumulus clouds completely change their shape.

How Nimbostratus Clouds Compare to Others

Nimbostratus clouds are unique because they can stretch across many levels of the sky. Other flat, layered clouds usually stay within one or two levels.

• Stratus clouds are low clouds, found from the ground up to about 6,500 feet (2,000 meters).
• Altostratus clouds are middle-level clouds. They form between about 6,500 feet (2,000 meters) and 23,000 feet (7,000 meters).
• Cirrostratus clouds are high-level clouds made of ice crystals. They can create beautiful halo effects around the sun. These clouds form very high up, sometimes over 60,000 feet (18,000 meters).

Nimbostratus clouds are most similar to cumulonimbus clouds and cumulus congestus clouds. This is because all three can grow very tall and bring moderate to heavy rain or snow. Other clouds like cumulus, stratocumulus, altocumulus, and cirrocumulus are quite different from nimbostratus.

See also

• Nimbostratus virga
• Cumulonimbus
• List of cloud types