Measuring Snow Experiment

Snow is great for play and science! This measuring snow experiment is easy and way cool. Couldn’t resist.

When scientists and meteorologists study snow, they can measure more than just how many inches have fallen.

Snow depth tells us how deep the snow is.

Snow water equivalent (SWE) tells us how much liquid water is contained in the snow. Imagine collecting a sample of snow, melting it completely, and measuring the water that’s left. That’s the snow water equivalent. We’re going to get more into these measurements in our two experiments.

Here in the southern U.S., when we get snow, the temperatures don’t typically drop down to single digits, so the snow tends to be wetter and heavier.

If you’ve ever scooped up snow, brought it inside, and waited for it to melt, you may have noticed something surprising:

Not all snow melts into the same amount of water.

We have enjoyed some melting snow experiments. Here are some things we have done over several snowfalls. We have created some lab sheets to go along with this measuring snow experiment. There are several experiment questions your kids can explore; we’ve included some ideas in the free worksheet packet. Take into consideration your weather forecast; if you’re expecting snow several days over the coming week, take several collections, record the data, and then make comparisons across the snowfalls. Was one snow lighter and fluffier? Did the outside temperatures vary? If so, how did affect measurements?

We live in the southern U.S., so snow is quite rare. But, you can measure snow from one winter to the next!

You can also have your children journal the types of snow they observe over one winter season or multiple winters using this types of snow journal.

Measuring Snow Experiment

We can use measurements to calculate the snow-to-liquid ratios. This ratio compares the depth of the snow with the amount of liquid water it contains.

A commonly used rule of thumb is a 10:1 snow-to-liquid ratio, meaning about 10 inches of snow contains approximately 1 inch of liquid water. (See the NOAA website here). However, the actual ratio can vary considerably depending on the type of snow and atmospheric conditions.

What Affects the Snow to Liquid Ratio?

Temperature is one factor that can affect how wet or fluffy snow is. Snow that falls when temperatures are near freezing is often wetter and denser, while colder temperatures can produce lighter and fluffier snow.

But temperature isn’t the only factor. Conditions inside the clouds affect the types of snow crystals that form, and wind can break or pack snow cyrstals. Seet or other frozen precipitation mixed with snow can also make a sample of snow we collect much denser.

That is why two snowfalls can have very different amounts of liquid wter, even when you collect the same depth of snow.

After last week’s snow fall, we decided to test this.

First, we scooped up a container of fluffy snow. There were approximately 9 inches of snow in the container.

We were also curious about the temperature of the snow. The temperature of our snow sample was 0°C (32°F), while the outside air temperature was 30°F.

We placed the container on the counter and allowed the snow to melt. The room temperature was 71.2°F.

As the snow warmed, we noticed something interesting. The snow began to melt, but at first no liquid water collected at the bottom of the container.

When we felt the snow, it was more like ice crystals and felt heavier than the fluffy snow we had originally collected. The temperature was increasing, also, due to the fact that the snow was shrinking away from the thermometer. Here are a few more photos.

When the snow melted, there was approximately 1 1/8 inches of water in the bottom of the container. If we started with approximately 9 inches of snow and ended up with approximately 1 1/8 inches of water, that is close to our 10:1 snow to rain ratio that is the standard rule. (NOTE: It is important that your container is the same size from top to bottom.)

One last note, we ended up with approximately 12 ounces of water.

Comparing Our Results Using Ratios

We started with approximately 9 inches of snow and ended with 1.125 inches of water. To calculate our snow-to-liquid ratio, divide the depth of the snow by the depth of the melted water:

9 ÷ 1.125 = 8

Our snow had a snow-to-liquid ratio of approximately 8:1. In other words, about 8 inches of this snow would contain approximately 1 inch of liquid water.

A commonly used rule of thumb is a 10:1 snow-to-liquid ratio, meaning that 10 inches of snow would contain about 1 inch of liquid water. Our 8:1 ratio tells us that our snow contained a little more water than the snow represented by the 10:1 rule of thumb.

Remember, snow doesn’t always follow the 10:1 ratio. Some snow is wet and dense, while other snow is light and fluffy. Temperature and other atmospheric conditions can affect how much liquid water is contained in a given depth of snow.

Try this for yourself and see how your results compare.

Download the Measuring Snow Experiment Worksheeets

Measuring Snow Experiment – More Measurements

We conducted some other measurements during another snow event. This event was much colder and there was more sleet and ice mixed into this event. For this we used:

measuring cup -liquid and “dry ingredient” measuring cups
snow
thermometer
kitchen scale
outdoor thermometer to measure the outside temperature (which can affect how

First, we weighed the empty measuring cup. Then, we filled it with snow, leveling the snow evenly at the top of the cup, and weighed it again. We subtracted the weight of the empty cup from the weight of the full cup to find the weight of the snow alone.

Next, we measured the depth of the snow in the container. Our sample was 2.5 inches deep.

We allowed the snow to melt completely and then measured the depth of the liquid water. After melting, we had 7/8 inch, or 0.875 inch, of water.

To calculate the snow-to-liquid ratio, we divided the depth of the snow by the depth of the melted water:

2.5 ÷ 0.875 ≈ 2.86

Our sample had a snow-to-liquid ratio of approximately 2.9:1. This means that about 2.9 inches of this frozen precipitation contained approximately 1 inch of liquid water.

That’s much more water than we found in our first snow sample, which had a snow-to-liquid ratio of about 8:1. Why such a big difference?

This winter storm included sleet, or ice pellets, mixed with the snow. Ice pellets are much denser than light, fluffy snow, so the same depth of mixed frozen precipitation can contain much more liquid water.

Our first cup of snow did melt down to just shy of 4 ounces of water.

We discussed how different “types” of snow could affect the amount of water.

The temperatures were in the single digits, so our snow was “powderier” than the snow we’ve had at just below freezing, which was wetter and heavier.

Temperature is one factor that can affect the amount of water in snow, but it isn’t the only one. Conditions in the atmosphere, the types of snow crystals that form, wind, and whether other types of frozen precipitation are mixed with the snow can make a difference.

Try this experiment again during another snowstorm and compare the outside temperature, the depth of the snow, and the amount of liquid water produced after the snow melts. Do you get the same snow-to-liquid ratio each time?