Melanie has a BS in physical science and is in grad school for analytics and modeling. Her research is in computational chemistry.

What Are Clouds?

Clouds are large groups of tiny water droplets (vapor) or ice crystals that cling to pieces of dust in the atmosphere.



Clouds are so important to the earth's weather that meteorologists (people who study the weather) also study the clouds and their movement. In fact, without clouds, it wouldn't rain or snow! They come in all different shapes and sizes. Some are really low to the ground and some are way high up in the sky.



Scientists have developed a system to classify the different types of clouds. Each cloud you see can be put into one of the many categories based on both their general shape and how high up they are in the atmosphere.

Video on the various cloud types (including less common types of clouds)

Funnel Clouds? Learn About Tornadoes

16 Astonishing Tornado Pictures

Learn about the different types of tornadoes and see amazing pictures of these violent storms. Find out out how tornadoes are ranked on the Fujita scale and see examples of F5 tornadoes.

Asperitas clouds

Lenticular cloud over a windmill farm

Lentcular cloud over a mountaintop

Mammatus clouds

Cirrus Clouds

These are the highest clouds in the atmosphere. Cirrus clouds are thin, wispy clouds that often appear on days with fair weather conditions and low winds. In fact, the word cirrus means "curl of hair" in Latin!



Because of the freezing temperatures high up in the atmosphere, these clouds are usually made up of ice crystals which give them a bright white appearance.



These clouds form in flat sheets, so they aren't as thick as the other types of clouds. Cirrus clouds are also spread out in patches, with large breaks of the sky in between them.



Since these clouds are so far from the ground, they aren't often affected by the changing weather on the earth's surface. Instead, they peacefully float along from west to east.

At any one time, there can be different kinds of clouds present. Here you can see puffy cumulus clouds set against a backdrop of cirrus clouds. Nicholas_T, CC-BY, via Flickr

Thin sheets of cirrus clouds PiccoloNamek, CC-BY-SA, via Wikimedia Commons

Did you know? Cirrus clouds are often a telltale sign that the weather is about to change for the worse.

Cumulus Clouds

Cumulus clouds are bright white and look like big puffs of cotton. The word cumulus is Latin for "heap" or "pile." This is because these clouds are sometimes extremely thick and tall and they often grow upward in size. An easy way to remember this is to think of the word accumulate, which means "to gather an increasing amount."



The bases of these clouds are often flat and the tops are usually composed of rounded sections. Cumulus clouds are vertically developing clouds which mean they can become extremely tall clouds.

Puffy cumulus clouds over a golden meadow PiccoloNamek, CC-BY-SA, via Wikimedia Commons

Stratus Clouds

Stratus clouds are thick, gray clouds that look like fog that hasn't touched the ground. In fact, these clouds sometimes are made up of fog that has lifted from the ground. As you may have guessed, these are low-altitude clouds, which means they are really close to the ground.



When someone says, "today is a gray and cloudy day", they are usually referring to these thick, uniform clouds. Stratus clouds often produce a light, drizzly rain or snow, especially when it's a nimbostratus cloud.

Stratus Clouds over Hardangervidda, Norway [public domain]

Nimbus Clouds

The word "nimbus" means rain in Latin, so these are the clouds that produce rain. Any cloud with the prefix nimbo or the suffix nimbus is a type of rain cloud. For example, a nimbostratus cloud is a stratus cloud that will cause rain or snow. Since stratus clouds are dull, gray, and featureless, nimbostratus clouds can be seen on gray, rainy days.



Another type of rain cloud is the cumulonimbus. Since cumulus clouds are the heaping, giants, cumulonimbus clouds are giant, heaping rain clouds. These clouds can be so huge that their bases start at only 1,000 feet above the ground with a top of 39,000 feet! These clouds, sometimes called thunderheads, form into the shape of an anvil which is a sure sign of a storm!



Heavy thunderstorms and even tornadoes are associated with this type of cloud (a tornado is a rotating column of air connected to a cumulonimbus cloud.)

Did you know? The term "cloud nine" comes from an atlas published in 1896 classifying clouds into ten types, with cumulonimbus clouds being the 9th type, or cloud nine!

A cumulonimbus cloud near White Canyon, Utah [public domain]

Cloud Name Type Latin Meaning Altocumulus Mid-level "high heap" Altostratus Mid-level "high sheet" Cirrus High-level "curl of hair" Cirrocumulus High-level "wispy heap" Cirrostratus High-level "wispy sheet" Cumulonimbus Vertical developing (all levels), rain "rain cloud" Cumulus Vertical developing (all levels) "heap" Nimbostratus Low-level, rain "rain sheet" Stratocumulus Low-level "heap & sheet" Stratus Low-level "sheet"

Mixing Up The Main Types

You may have noticed from the last section on the different kinds of nimbus clouds, that different clouds types exist beyond just cirrus, cumulus, stratus, and nimbus. You've learned about nimbostratus and cumulonimbus clouds, so let's go over some of the other kinds.



Most clouds can be described by mixing and matching the terms cirrus, cumulus, stratus, and nimbus. For example, there are cirrocumulus clouds which are vertically developing (and blotchy) clouds way high up in the atmosphere.



Cirrostratus clouds are thin, wispy sheet clouds. What's cool about these clouds is that they can cause a halo-like appearance around the sun or moon! This is caused by the light refracting through the cloud's vapor.



There aren't any clouds called cirronimbus or nimbocirrus. This is because cirrus clouds seldom rain. When they do rain, it'll drop tiny ice crystals that will evaporate before they hit the ground.



The chart to the right shows some of the most common types of clouds, what kind they are, and what their name means in Latin.

Lenticular clouds David Brodbeck, cc-by, via Flickr

Did you know? The average cumulus cloud weighs 1.1 million pounds.

Strange Cloud Formations

Aside from the common clouds that you may already be familiar with, there are a few types of clouds that are completely different from the ones previously mentioned. These rare (and weird looking clouds) occur under special conditions.



Lenticular clouds - These clouds are sometimes called "saucer clouds" due to their unearthly UFO-type appearance. Lenticular clouds have a lens-like appearance and form over high altitudes (over a mountain or a large hill.)

The setting sun reflecting off altocumulus clouds LivingShadow, CC-BY-SA, via Wikimedia Commons

The sun shining through altostratus clouds LivingShadow, CC-BY-SA, via Wikimedia Commons

Cirrus clouds over Warsaw, Poland Blueshade, CC-BY-SA, via Wikimedia Commons

Cirrocumulous clouds Fir0002, CC-BY-SA, via Wikimedia Commons

Cirrostratus clouds often create a ring around the sun or moon. Fir0002, CC-BY-SA, via Wikimedia Commons

Cumulonimbus clouds over Wyandotte County, Kansas. These clouds often produce powerful storm. Matt, CC-BY, via Flickr

Cottony cumulus clouds over Klecknersville, Pennsylvania. Nicholas_T, CC-BY, via Flickr

Heavy nimbostratus clouds such as these make for a gloomy day PiccoloNamek, CC-BY-SA, via Wikimedia Commons

Disintegrating stratocumulus clouds LivingShadow, CC-BY-SA, via Wikimedia Commons

Thick sheets of stratus clouds over a pine forest LivingShadow, CC-BY-SA, via Wikimedia Commons

Strange Fact!

When it's too hot, trees release substances known as monoterpenes which stimulates cloud formation cooling off the trees (D. V. Spracklen (2008). "Boreal forests, aerosols and the impacts on clouds and climate".)



© 2012 Melanie

XD SI QUE on April 14, 2020:

900% awesomeness :) helps a lot i had a test and this help me get a 100% thank you a lot

joshua dye on April 14, 2020:

100% awsomness:]:]!

Noah Demmitt on April 01, 2020:

This has helped me a lot in science and makes me interested in it. : )

xd lu,n on March 23, 2020:

clouds are so cool literaly

maley on March 16, 2020:

wow so cool i love clouds and this help me a lot

drtgvgrtyghbnvr on February 04, 2020:

wow clouds are cool and weird at the same time

victor jayawardena on December 17, 2019:

very helpful and interesting article.

Zoster on May 29, 2019:

I had to take a final exam including the different type of clouds and their subcategories, and boy did this help me pass!

Rediah comment is inappropriate!!!! on May 21, 2019:

The pictures of the lenticular clouds are very interesting. These can be seen around Mt. Rainier

Katarianna on May 15, 2019:

I love the pictures! They are very beautiful.

Luca on May 11, 2019:

Lol i liked this and i did this in my homework,

Sienna on April 26, 2019:

This was a very helpful and interesting site. This allowed me to pass my test! *Highly recommended*

Megaman on March 15, 2019:

col :D

Emily Jeweler on March 13, 2019:

this was for my brother's and my school and this was our assignment, and was the perfect way to learn about and see these awesome clouds!

Butterfly Warrior on February 26, 2019:

Helping to teach a student to take his GED, and your site has been a life saver as it is concise and easy to understand for both the forever learner and the one I have to drag to the study table everyday. Blessings and I hope you are able to take your passion and continue to use it to teach the world able what we see everyday but know little to nothing about.

Butterfly Warrior

Aromah on November 14, 2018:

Thx so much, so helpful... trying to study for geo is way easier now

Vents chug on November 14, 2018:

This was very helpful thank you

Rochelle on May 20, 2018:

This article was very helpful as I assisted my brother in his grade 4 social studies project! Thanks for the succinct information & very handy pictures.

Rachel Miller from Michigan U.S.A. on March 22, 2018:

This is totally great! Thank so much! I got an A with help of this article and a few others.

rediah on October 01, 2017:

it was okay . It wasn't mindblowing and there are many jobs out their and this one is S H I T

Melissa Flagg COA OSC from Rural Central Florida on September 30, 2017:

Wow, now I know why this article is being used in schools! It's fascinating! We have altocumulus clouds and cirruscumulus clouds frequently here in Central Florida. The next time I see one you can bet I'll be showing off my newfound knowledge LOL!

Kanika on September 28, 2017:

I love the pictures and the informative writing . I never thought clouds were that interesting

Becky Callahan on August 10, 2016:

Wonderful informative writing! Loved your photos too.

David Warren from Nevada and Puerto Vallarta on April 02, 2012:

Well done! As a single engine pilot and glider club member clouds are part of my life. Love the hub! Voted up and awesome.

Sharon Smith from Northeast Ohio USA on March 26, 2012:

Because of my fascination with clouds, I always thought I should be a meteorologist. But way back after high school, it was NOT a cool job at that time. And so I never did it. Stupid me. I think I would have really loved it. Great hub Mel!!!

Sharyn

cardelean from Michigan on March 14, 2012:

I remember learning about clouds in elementary school and really enjoyed it. Unfortunately I've forgotten most of it so your hub was a great refresher along with some new and interesting facts. I loved the pictures too. Makes me wish we did a cloud unit in fourth grade!

Rachel Vega from Massachusetts on March 11, 2012:

Oh, I thought I had commented on this one! Sorry about that.

I love this Hub and the pictures are amazing. I voted Up, beautiful and interesting.

Glenn Stok from Long Island, NY on March 09, 2012:

I had learned about clouds in high school, but I forgot most of it. I enjoyed this thorough review and found it very useful. Most people depend on weather forecasts with9out realizing that they can usually predict the local weather just by looking up and observing the types of clouds. Well done, voted up.

Zulma Burgos-Dudgeon from United Kingdom on March 09, 2012:

Enjoyed reading this hub. Good job.

Om Paramapoonya on March 08, 2012:

How interesting! I never thought that clouds could be classified into so many categories. I guess cumulus clouds are my favorite; they remind me of cotton candy!

Teresa Coppens from Ontario, Canada on March 08, 2012:

Fantastic information hub on clouds. If my youngest son has to do a project in this area I will send him to this hub for research. Well done and beautiful.

Marcy Goodfleisch from Planet Earth on March 08, 2012:

What a terrific hub! I've heard these terms for years, but never researched all the meanings. You've provided a simple, easy to understand glossary of the names and what they mean. I love it! Thanks for publishing this hub.

Voted up, useful and interesting.

Alissa Roberts from Normandy, TN on March 08, 2012:

Very interesting hub! I enjoyed looking at all the different kinds of cloud pictures. We definitely have stratus clouds in the sky in TN today - looks really dreary and depressing here! Great job - voted up!

Carolee Samuda from Jamaica on March 08, 2012:

Wonderful lesson on clouds.This was very engaging and a great refresher course. This was once of my favourite things to learn about in high school.

James Kenny from Birmingham, England on March 08, 2012:

A really beautiful hub. Clouds are often overlooked, its easy to forget that there are so many types. I genuinely did not know about Cirrus clouds signalling a change for the worse weather wise; so thanks very much for sharing.

diogenes from UK and Mexico on March 08, 2012:

Very interesting and useful hub on creatures nearly always present in the British skies. \i hate clouds and like deserts which plays hell wid 'em.

Cloudy means unhappy ...sunny, happy.

Voted up anyway

Bob

Michael S from Danville, VA on March 08, 2012:

I enjoyed this, Melbel. Moreover, I was drawn in by the beautiful photographs. Thanks!

Daisy Mariposa from Orange County (Southern California) on March 07, 2012:

Melanie,

Thanks for publishing this very informative Hub. If I were still in school and had to do a report about clouds, your article would provide perfect resource material.

Your choice of photographs was excellent. They added so much to your article.