Types of Clouds

When you look at the sky, you will see different cloud formations. How many types of clouds do you know? You are probably familiar with the main cloud types. However, clouds are further classified into species, varieties and even supplementary features that appear with the main cloud types. Understanding the different cloud formations is very important to help you foretell and prepare for the upcoming weather system.

Why are there Different Types of Clouds?

The reason why you see different types of clouds in the sky is because clouds form at different elevations and temperatures. They may contain water droplets, ice crystals or a combination of both. Clouds get their shapes from the surrounding air which frequently changes; at one point they are calm and sometimes very windy. Winds always push and pull at the clouds, pressing and stretching them toward different directions. That is why clouds come in different forms and shapes. In fact, they are classified according to an assortment of genera or main groups, species and varieties.

Main Types of Clouds

There are ten main types of clouds or genera grouped based on their appearance and height in the atmosphere.

  • High Level Clouds

These clouds are found more than 6,000 meters (or 20,000 feet) from the Earth’s surface. High level clouds are primarily made up of ice crystals due to below freezing temperatures at the cloud level. These clouds exhibit a thin, white appearance and provide spectacular array of colors most especially if the sun run low in the horizon. High level clouds use the prefix “cirro”, a Latin word which means “wisps of hair”.

    • Cirrus Clouds

These clouds display a hair-like appearance in thin and white narrow bands or patches. Cirrus clouds are indicators of good weather.

    • Cirrocumulus Clouds

Cirrocumulus appears like cotton balls floating in the sky in white patches or sheets and without shading. The cloud elements could either be merged or separated and almost regularly arranged. 

    • Cirrostratus Clouds

Cirrostratus clouds are thin clouds spread across the sky and give rise to halo effect from the sun. These clouds exhibit smooth, hair-like white appearance and are strong indication of an upcoming rain or snow.

  • Middle Level Clouds

These clouds are found at middle altitude anywhere between 2,000 meters and 6,000 meters (or 6,500 feet and 20,000 feet) from the ground. Middle level clouds are largely made up of water droplets though they may also be made up of ice crystals if the temperature at the cloud level is sufficiently cold. Clouds belonging to the middle level group have the Latin prefix “alto” which connotes medium level.

    • Altocumulus Clouds

These clouds are often confused with high level cirrocumulus clouds. However, unlike cirrocumulus, some parts of altocumulus clouds have gray-toned shade appearing either in patches or layers. Altocumulus is a good indicator of thunderstorm later in the afternoon.

    • Altostratus Clouds

Altostratus appears as thin sheets or layers of clouds in gray or bluish hue that partly or completely covers the sky.  This cloud type gives rise to hazy or fuzzy sky. A thickening altostratus cloud signals precipitation.

    • Nimbostratus Clouds

Nimbostratus Clouds are classified under middle cloud level, though it may also appear in the lower cloud level. Nimbostratus is a featureless cloud formation appearing as thick, gray clouds covering the entire sky. These clouds produce heavy precipitation as either rain or snow.

  • Low Level Clouds

Low level clouds are found at lower elevations less than 6,500 feet from the ground. These clouds primarily contain water droplets although they may also hold ice particles under cold temperatures. Low level clouds use the prefix “strato” which is a Latin word for “layered”.

    • Stratus Clouds

These clouds appear close to the surface covering most parts of the sky and resemble fog. Stratus clouds have uniform bases in gray color which produce light drizzle.

    • Stratocumulus Clouds

Stratocumulus is very common during overcast days and is identified as a low-lying cloud form. They appear in patches or layers of gray or whitish, with lumpy shapes and do not produce heavy precipitation. 

  • Clouds with Vertical Development

Clouds in this category occupy the three cloud levels with bases anchored at the low level and grow at greater heights over 39,000 feet from the ground. Clouds with vertical development use the prefix “cumulo”, a Latin word for “heap” or “pile”.

    • Cumulus Clouds

Cumulus clouds are clouds showing gray flat bases with lumpy white tops like floating cotton balls in the sky. Although these clouds are often called fair water clouds, cumulus with dense gray bases are strong indication of impending rain or snow.

    • Cumulonimbus Clouds

These clouds are also called thunderstorm clouds because their formation announces an approaching severe weather system. This is especially true when the tops of cumulonimbus clouds exhibit an anvil pattern or domes indicating intense thunderstorm updraft.  

Species Associated with Main Types of Clouds

Clouds are also classified into species based on their shape, size and the arrangement of cloud elements.

  • Capillatus

This cloud species only occurs in the cumulonimbus genus and is distinguished by the cap-like structure atop cumulonimbus cloud.

  • Calvus

Calvus is exclusive to cumulonimbus clouds and manifests whitish projections on the upper part of cumulonimbus cloud.

  • Congestus

This particular species exhibits cauliflower-shaped tops specific to cumulus clouds.

  • Castellanus

These are clouds having tower-like projections which occur in the genera of cirrus, cirrocumulus, altocumulus and stratocumulus.

  • Fibratus

Clouds having thin irregular filaments that mainly occur in cloud genera cirrus and cirrocumulus.

  • Fractus

Characterized by shredded cloud elements, this species occurs in cumulus and stratus clouds.

  • Floccus

Clouds of this species exhibit small bunch of cloud elements with shredded bases.  It is found in cirrus, cirrocumulus and altocumulus clouds.

  • Humilis

Humilis shows slight vertical development and is only found in cumulus genus.

  • Mediocris

This species only arise in cumulus clouds showing moderate vertical development.

  • Unicus

It has a hook-like appearance and is exclusive to cirrus genus.

  • Stratiformis

Stratiformis is characterized by extensive horizontal development that found in altocumulus, stratocumulus and sometimes, cirrocumulus genera.

  • Nebulosus

This cloud species appear like a veil with no sharp details.  This occurs in the cirrostratus and stratus genera.

  • Spissatus

It has adequate thickness with a tinge of gray and found in cirrus genus.

  • Lenticularis

These are clouds showing lens-shaped elements with clear outlines found in cirrocumulus, altocumulus and stratocumulus.

Varieties and Supplementary Features 

Cloud genera are further classified into varieties and supplementary features.

  • Varieties
    • Intortus – twisted cloud filaments
    • Duplicatus – cloud layers or patches that are doubled or partly merged
    • Undulatus – clouds showing undulations or waves
    • Radiatus – having rays or parallel bands converging in one point in the horizon
    • Lacunosus – clouds that have holes
    • Perlucidus – thin cloud layer making sun or moon visible through it
    • Translucidus – clouds that are sufficiently transparent
    • Opacus – thick and shady and completely covers the sun or moon
    • Vertebratus – clouds showing like fish skeleton or ribs


  • Supplementary Features
    • Incus – appearing like anvil
    • Praecipitatio – with precipitation reaching the ground
    • Arcus – showing an arc-like structure usually rolling horizontally
    • Mamma – hanging sac-like structures underneath the anvil
    • Virga – produces precipitation that doesn’t reach the ground  
    • Pannus – ragged or shredded cloud elements
    • Pileus – cap-like structure atop cumuliform clouds
    • Tuba – funnel-shaped clouds reaching downwards to the ground
    • Velum – similar with pileus but quite dull


You don’t have to be a weather forecaster to predict the upcoming weather or be a professional cloud collector to value the different types of clouds. By understanding the various types of clouds, you can prepare for the kind of weather conditions they bring and appreciate the beauty of clouds in the sky.

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