What If? Lab
What if clouds were made of candyfloss?
Fluffy clouds look like candyfloss. But real clouds are made of tiny drops of water and bits of ice. What if they were sweet and sugary? Let's imagine it with Olly!
Puffy clouds look like giant balls of candyfloss (cotton candy), but they are really made of tiny water droplets or ice crystals, and the water in a big one weighs about as much as 100 big African elephants. Imagine clouds spun from sugar instead, and find out what real clouds are made of.
NOAA describes clouds as water droplets or ice crystals condensed on tiny particles, and USGS estimates that a one-cubic-kilometer cumulus holds about 500,000 kilograms of water. This playful thought experiment swaps that water for spun sugar to explore cloud composition, weight and rain.
The big question
Look up! Some clouds look soft and fluffy, like candyfloss.
What if clouds really were made of candyfloss? What might happen?
On a sunny day, puffy white clouds can look just like candyfloss, the sweet, fluffy treat also called cotton candy. NOAA even describes these cumulus clouds as looking like white, fluffy cotton balls.
What if clouds really were spun from sugar? This is a silly idea, but it is a great way to learn what real clouds are. You can follow three paths: what clouds are made of, how heavy a cloud is, and what might happen to a candyfloss cloud in the rain.
Cumulus clouds, which NOAA describes as resembling white, fluffy cotton balls, owe their look to countless droplets formed where rising moist air condenses.
This thought experiment replaces cloud water with candyfloss, sugar melted and spun into threads, and uses the contrast to examine cloud microphysics: how droplets form, why a cloud with real mass stays aloft, and how rain begins. The candyfloss world is pure fantasy; every claim about real clouds comes from NOAA, USGS and university sources.
Explore the idea
Make a prediction
What are real clouds made of?
What are real clouds made of?
According to NOAA, clouds consist of…
- Tiny drops of water or bits of ice
- Fluffy cotton
- Smoke from chimneys
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Established fact
Clouds are made of tiny water drops and ice. A big cloud is very heavy.
Clouds are water droplets or ice crystals formed on tiny specks; a big cumulus holds about 500,000 kg of water (NOAA, USGS).
Clouds are droplets and ice condensed on nuclei; a 1 km³ cumulus holds about 500,000 kg of water and floats because cloud air is less dense than dry air (NOAA, USGS).
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An idea scientists discuss
Candyfloss clouds are pretend. We imagine what might happen.
Clouds can't be made of candyfloss. What might happen if they were is a playful idea that helps us learn about real clouds.
Every candyfloss-cloud outcome here is fantasy reasoning, used only to contrast with real cloud physics.
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Established fact
Puffy clouds look like big, white cotton balls.
Cumulus clouds look like white, fluffy cotton balls, with flat bottoms where rising moist air condenses.
Cumulo-form clouds appear as white, fluffy cotton balls whose flat bases sit at the altitude where rising moisture condenses (NOAA JetStream).
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Established fact
Clouds form when water in the air cools and turns into tiny drops or ice.
Water vapor turns into clouds when it cools and condenses back into liquid water or ice, on a seed such as dust or pollen.
Water vapor condenses into cloud when it cools, needing a solid seed such as dust, pollen, a droplet or an ice crystal (NOAA NESDIS).
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Established fact
Every cloud drop has a tiny speck of dust or salt in the middle.
Every cloud droplet has a speck of dirt, dust or salt at its center, but it is still almost pure water.
Cloud condensation nuclei such as smoke, sea spray or soil attract water; every droplet has one at its core yet is essentially pure water (NOAA JetStream).
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An idea scientists discuss
A candyfloss cloud might be made of sugar, with no water drops inside.
A candyfloss cloud might be made of sugar threads instead of water droplets, so it might not grow or change shape the way real clouds do.
A sugar cloud might lack condensation and evaporation entirely, so the constant reshaping of real clouds might not happen; this is fantasy reasoning.
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Established fact
A big cloud holds lots and lots of water.
A cumulus cloud one kilometer long, wide and tall holds about 500,000 kilograms of water droplets.
With a density of about 0.5 g/m³, a 1 km³ cumulus holds about 500,000 kg (1.1 million pounds) of droplets (USGS Water Science School).
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Established fact
The water in a big cloud weighs about as much as 100 big elephants.
A big African bush elephant can weigh about 5,000 kilograms, so that much water weighs about as much as 100 big elephants.
African bush elephants weigh 2,000 to 6,100 kg (African Wildlife Foundation); 500,000 kg is about 100 large ones of 5,000 kg each.
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Established fact
A cloud floats because the air below it is heavier.
Clouds float because the moist air in a cloud is less dense than the dry air around it, the way oil floats on water.
Cloud material is less dense than the same volume of dry air, so the cloud floats on the drier, denser air beneath (USGS).
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An idea scientists discuss
We don't know if a candyfloss cloud might float or drop.
A candyfloss cloud might float or might sink; we can only guess, because real clouds are never made of sugar.
Whether a sugar cloud might stay aloft depends on properties no real cloud has; any answer here is speculation.
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Established fact
When cloud drops get too heavy, they fall as rain.
Droplets in a cloud grow as more water condenses onto them. When they are too heavy to stay up, even with rising air, they fall as rain.
Droplets grow by condensation until they are too heavy to remain suspended despite updrafts; below freezing, ice crystals form and can fall as snow (NOAA NESDIS).
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Established fact
Candyfloss is made of sugar. Sugar dissolves in water.
Candyfloss is almost entirely sugar, melted and spun into thin threads. It soaks up moisture, and the threads dissolve in water.
Cotton candy is almost entirely sucrose, melted (at 190 °C) and spun into threads that absorb moisture, clump as they crystallize, and dissolve in water (USC Illumin).
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An idea scientists discuss
In the rain, a candyfloss cloud might shrink and wash away.
A candyfloss cloud might turn into sticky clumps on a damp day and dissolve in the rain, instead of making rain itself.
A sugar cloud might collapse in humid air and dissolve in liquid water, so it might never produce precipitation; this is fantasy reasoning, not prediction.
In our world
Real clouds are made of tiny drops of water. Very cold clouds are made of bits of ice.
Each tiny drop forms on a speck of dust or salt.
NOAA explains that clouds form when water vapor, the invisible gas form of water, rises, cools and condenses back into liquid water or ice. To condense, the vapor needs something solid to cling to: a speck of dust, pollen or salt.
So every cloud droplet has a tiny speck at its center, but it is still almost pure water. High, wispy cirrus clouds are made of ice crystals. Droplets are always forming and evaporating, which is why clouds change shape.
NOAA: water molecules alone are too small to bond into droplets, so they condense onto cloud condensation nuclei, such as smoke, ocean spray or wind-blown soil, which attract water. Every droplet therefore has a speck of dirt, dust or salt at its core, yet remains essentially pure water.
Condensation begins when rising air expands, cools at the dry lapse rate of about 9.8 °C per kilometer and reaches saturation. Because drier air mixes in, condensation and evaporation run together, so clouds constantly form, dissipate and change shape. Cirro-form clouds are composed of ice crystals.
Imagine candyfloss clouds
Let's pretend the clouds are pink, sweet candyfloss.
When it rains, might they wash away? Let's find out what sugar does with water!
Now imagine every cloud spun from sugar threads. It sounds delicious, but think about how candyfloss behaves. It soaks up water from the air, and its threads dissolve in water.
So candyfloss clouds might shrink on damp days and dissolve in the rain. They might not make rain at all, because rain starts as water droplets that grow too heavy to float. These are playful ideas, not facts: real clouds are water and ice.
Spun sugar is hygroscopic: the USC engineering article on cotton candy notes that it absorbs moisture, that moisture induces crystallization into clumps, and that the threads dissolve in water.
A candyfloss cloud might therefore collapse in humid air and dissolve in any real rain. It might also lack the process that makes precipitation: droplets growing by condensation until updrafts can no longer hold them. Whether a sugar cloud might even stay aloft is unknown. All of this is fantasy reasoning used to highlight real cloud physics.
How a heavy cloud floats
A big cloud holds lots of water. It is as heavy as about 100 big elephants!
But it floats, because the air under it is even heavier.
Clouds look light, but they are heavy. USGS worked out that a puffy cumulus cloud one kilometer long, wide and tall holds about 500,000 kilograms of water droplets. A big African bush elephant can weigh about 5,000 kilograms, so that is about as heavy as 100 big elephants.
So why doesn't it fall? USGS explains that the moist air in a cloud is less dense than the dry air around it, so the cloud floats on the air below, a bit like oil floats on water.
USGS estimates a cumulus cloud's water using a density of about 0.5 gram per cubic meter: a 1 km³ cloud of one billion cubic meters holds about 500,000,000 grams, or 500,000 kilograms (1.1 million pounds) of droplets. The African Wildlife Foundation gives African bush elephants a weight of 2,000 to 6,100 kilograms, so the cloud's water matches about 100 large elephants of 5,000 kilograms each.
USGS attributes the cloud's buoyancy to density: cloud air is less dense than the same volume of dry air, so the cloud floats on the denser air beneath.
From cloud to rain
Tiny cloud drops bump together and grow. When they get too heavy, they fall. That is rain!
If the air is freezing, they can fall as snow.
Inside a cloud, NOAA explains, water keeps condensing onto droplets and they grow. When the droplets get too heavy to stay up, even with rising air pushing on them, they fall as rain. If the cloud is below freezing, ice crystals form, and if the air is freezing all the way down, you get snow.
Candyfloss is different. A University of Southern California engineering article explains that it is almost all sugar, melted and spun into fine threads, and that the threads dissolve in water.
NOAA: droplets grow as more water condenses onto them; when they are too heavy to remain suspended despite updrafts, they fall as rain. Below 0 °C, ice crystals form, giving snow if the whole column is freezing, while alternating warm and cold layers produce other precipitation, such as hail.
Candyfloss, by contrast, is almost entirely sugar. The USC article describes sucrose melting at 190 °C and cooling into disordered threads before it can recrystallize. NOAA adds that clouds look white because their droplets, similar in size to light waves, scatter all colors equally.
Amazing facts
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Clouds look white because their tiny drops spread out all the colors of sunlight the same amount.
Clouds look white because their tiny droplets scatter all the colors of sunlight equally. Thick clouds look gray because less light gets through.
Cloud droplets are similar in size to the wavelengths of sunlight, so Mie scattering scatters all colors equally and clouds look white; thick clouds appear gray (NOAA JetStream).
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Long ago, people made spun sugar by hand with a knife!
A cookbook from 1786 by Elizabeth Raffald explained how to make spun sugar by hand, by moving a knife dipped in melted sugar so a thread followed it.
Elizabeth Raffald's 1786 cookbook described hand-spinning sugar threads with a knife; machine-spun sugar later became cotton candy (USC Illumin).
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In 1904, people at a big fair bought candyfloss made by a machine.
William Morrison and John Wharton applied for a patent on a candy machine in 1903 and used it to sell cotton candy at the 1904 World's Fair.
Morrison and Wharton's 1903 patent application described a rotating pan that flings melted sugar into silk-like filaments; they sold cotton candy at the 1904 World's Fair (USC Illumin).
Words to know
- water vapor
- water in the form of an invisible gas in the air
- condense
- to change from a gas into a liquid, like vapor turning into droplets
- cloud droplet
- a tiny drop of water in a cloud, too small to fall as rain
- cumulus
- a puffy, white cloud that looks like a cotton ball
- density
- how much mass is packed into a certain amount of space
- candyfloss
- a sweet treat of sugar spun into thin threads, also called cotton candy
Discovery challenge
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What is in the middle of every tiny cloud drop?
What is at the center of every cloud droplet?
According to NOAA, the core of every cloud droplet is…
- A speck of dust, dirt or salt
- A grain of sugar
- A tiny bubble of helium
Show the answer
A speck of dust, dirt or salt
A tiny speck of dust, dirt or salt!
A speck of dirt, dust or salt, but the droplet is still almost pure water.
…a cloud condensation nucleus such as dirt, dust or salt (NOAA JetStream).
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A big fluffy cloud holds lots of water. How heavy is all that water?
The water in a cumulus cloud one kilometer on each side weighs about as much as…
USGS estimates about 500,000 kg of water in a 1 km³ cumulus. That mass is about the same as…
- As heavy as about 100 big elephants
- As light as one feather
- As heavy as one cat
Show the answer
As heavy as about 100 big elephants
About 100 big elephants! But it still floats.
About 100 big African elephants of about 5,000 kilograms each: roughly 500,000 kilograms of water.
…about 100 large African bush elephants of 5,000 kg each (USGS cloud figure; African Wildlife Foundation elephant weights).
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What happens when cloud drops get too heavy?
What happens when droplets in a cloud grow too heavy to stay up?
When droplets outgrow what the cloud's updrafts can support, they…
- They fall as rain
- They float higher
- They turn into sugar
Show the answer
They fall as rain
They fall down as rain!
They fall as rain, or as snow if the air is freezing.
…fall as precipitation: rain, or snow in a freezing column (NOAA).
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What is candyfloss made of?
What is candyfloss (cotton candy) almost entirely made of?
Cotton candy consists almost entirely of…
- Sugar
- Water drops
- Cotton
Show the answer
Sugar
Sugar, spun into thin threads.
Sugar, melted and spun into thin threads.
…sucrose, melted and spun into disordered threads (USC Illumin).
Experiments to try
- Watch What If? Lab What if there were no clouds? Clouds shade the ground by day, send heat back down at night and are where rain comes from. Imagine a sky with no clouds at all, and follow what might happen to hot days, cold nights, rain and even the colors of the sky.
- Watch What If? Lab What if we could see the wind? Wind is moving air, and air is invisible. So people watch what the wind moves: smoke, leaves, flags, clouds and kites. Scientists even make wind maps from satellite pictures. Imagine the wind suddenly becoming visible, and follow the swirls, maps and kites that might appear.
- Watch What If? Lab What if the ground were made of limestone? Limestone is a rock that rainwater slowly dissolves. Over thousands of years, water seeping through it carves caves, opens sinkholes and bubbles back up as springs. About a fifth of the land in the United States is already this kind of landscape, called karst. Imagine the ground everywhere were limestone, and find out what would happen to the rain.
- Watch What If? Lab What if the Sahara turned green? Thousands of years ago, the Sahara Desert was a land of grass, wetlands and lakes, where cave paintings show hippos in watering holes. A slow wobble of Earth on its axis brought stronger monsoon rains. Find out why the Sahara was green, why it dried, and what might change if it turned green again.
Explore next
- Watch What If? Lab What if there were no clouds? Clouds shade the ground by day, send heat back down at night and are where rain comes from. Imagine a sky with no clouds at all, and follow what might happen to hot days, cold nights, rain and even the colors of the sky.
- Watch What If? Lab What if we could see the wind? Wind is moving air, and air is invisible. So people watch what the wind moves: smoke, leaves, flags, clouds and kites. Scientists even make wind maps from satellite pictures. Imagine the wind suddenly becoming visible, and follow the swirls, maps and kites that might appear.
- Watch What If? Lab What if the ground were made of limestone? Limestone is a rock that rainwater slowly dissolves. Over thousands of years, water seeping through it carves caves, opens sinkholes and bubbles back up as springs. About a fifth of the land in the United States is already this kind of landscape, called karst. Imagine the ground everywhere were limestone, and find out what would happen to the rain.
- Watch What If? Lab What if the Sahara turned green? Thousands of years ago, the Sahara Desert was a land of grass, wetlands and lakes, where cave paintings show hippos in watering holes. A slow wobble of Earth on its axis brought stronger monsoon rains. Find out why the Sahara was green, why it dried, and what might change if it turned green again.
- Watch Try it What If? Lab What if Earth had no atmosphere? Earth's air works like a jacket: it keeps heat in and carries it around. Take the air away in our model of a sandy patch of ground on the equator, and the coldest part of the night drops from about 13 °C to about 2 °C.
- Watch Try it What If? Lab What if there were no greenhouse gases? Greenhouse gases such as carbon dioxide and water vapor hold some of Earth's heat in, like a blanket. Take them all away in our energy-balance model and Earth's average temperature falls from about 15 °C to about −19 °C, well below freezing.
- Watch Try it What If? Lab What if there were more greenhouse gases? Adding greenhouse gases makes it harder for Earth's heat to escape, so the planet warms until it balances again. In our model a small change in how freely heat escapes warms Earth by about 2.6 °C, and the oceans make the warming take years.
- Watch Try it What If? Lab What if Earth were covered in ice? White ice bounces sunlight back to space, so an icy planet soaks up less of the Sun's warmth. In our energy-balance model, making Earth reflect 60 percent of its sunlight instead of 30 percent drops its average temperature from about 15 °C to about −23 °C.
For parents & teachers
What children will learn
- Clouds are made of tiny water droplets or ice crystals that form on specks of dust, pollen or salt.
- A cloud has real weight, about 500,000 kg of water in a large cumulus, yet floats on denser dry air.
- Rain falls when cloud droplets grow too heavy to stay up.
- A playful what-if can teach real science when facts and fantasy ideas are kept clearly apart.
Recommended ages: 4 to 17 · About 15 minutes
Talk about it
- What do clouds look like to you? Which ones look most like candyfloss?
- How can something as heavy as 100 big elephants float in the sky?
- Which parts of this experiment are real science, and which are just for fun?
Try at home or in class
- Put a small tuft of candyfloss on a plate and add a few drops of water with a spoon or dropper. Watch the threads disappear where the water lands: the USC article explains that spun sugar soaks up moisture and dissolves in water.
- Go cloud spotting with NOAA's Four Core Types of Clouds: look for fluffy cumulus 'cotton balls' and thin, wispy cirrus made of ice, and draw what you see.
Key vocabulary: water vapor, condense, cloud droplet, cumulus, density, candyfloss
Where these facts come from
- What Makes It Rain? , NOAA NESDIS
- How Clouds Form , NOAA JetStream
- The Four Core Types of Clouds , NOAA JetStream
- The Color of Clouds , NOAA JetStream
- How Much Does a Cloud Weigh? , USGS Water Science School
- African bush elephant , African Wildlife Foundation
- Cotton Candy: Carnival Snack to Medical Wonder , Illumin, University of Southern California Viterbi School of Engineering
Checked, not yet human-reviewed. Last updated October 24, 2026. Spotted a mistake? Tell us.