Rain to Snow Calculator (2023)

Our rain to snow calculator lets you calculate the expected rain to snow ratio based on the temperature outside. You might think, why would I need to know the rain-to snow ratio?
Have you ever looked around and wondered, instead of all this rain, how much snow would have fallen if it was colder?
This tool can also let you know if you should take an umbrella 🌂, or if you need your warm coat in case it snows? How many times have you wondered before leaving home?

This rain to snow calculator will answer all your questions - whether you are researching a school project or just had this random thought on a rainy day on how to convert inches of rain to snow.

Rain to snow ratio

The ratio of rain to snow or snow to rain depends on certain factors:

  • Temperature;
  • Humidity;
  • Precipitation;
  • Windchill; and
  • Atmospheric lift.

Most weather services say that, on average, the amount of snow is 10 times the rainfall volume, that is, 1 inch of rain is equivalent to 10 inches of snowfall.
If the snow is dense and molecules are tightly packed, then the ratio is 1:8. This ratio is not only dependant on temperature but requires a particular amount of windchill as well. If the texture of the snow is more fluffy and powder-like ❄️ then, depending on the temperature, the ratio can be anywhere from 1:20 to 1:50.

(Video) What Is The Average Ratio Of Rainfall To Snowfall?

Our rain to snow calculator takes the amount of rain in inches as input and calculates the inches of snow you might expect based on that amount of rain. Also, our rain to snow conversion is dependant on temperature, and so you should choose the most appropriate range. That is why you might not see our calculator use the 1:8 ratio of rain to snow, as it requires a certain amount of windchill, which is unfortunately not taken into account when performing this rain to snow conversion.
The formula created for the rain to snow conversion is given below:

Snow = Rain × SC


  • "SC" - Snow coefficient, a numeric value based on the atmospheric temperature.

All you need to do is know the temperature of your surroundings, find the corresponding snow coefficient and multiply it by the amount of rain in inches. The result is the amount of snow in inches.
The rain to snow conversion is explained in detail in the next section.

Rain to snow conversion

The most important factor that affects the rain to snow conversion is temperature. The amount of snow that one inch of rain will produce at varying temperatures is given in the table below. This will give you a better understanding of how the rain to snow calculator works and how you can convert any number of inches of snow to rain or rain to snow.

Temperature (°F)

Temperature (°C)

Snow (inches)

34 to 45 °F

1 to 7 °C


27 to 34 °F

-3 to 1 °C


20 to 27 °F

-6 to -3 °C


15 to 19 °F

-9 to -7 °C


10 to 14 °F

-12 to -10 °C


0 to 9 °F

-18 to -13 °C


-20 to -1 °F

-29 to -18 °C


< -20 °F

<-29 °C


We know that the temperature must be at or below freezing point for rain to turn into snow. Using the above table, you can convert rain to snow or snow to rain at your fingertips 🖐️.

If you've come across a situation where you can not use the rain to snow calculator, or you may want to teach someone how it is used and how the calculations are found, you need to follow these instructions:

  • Inches of rain to snow

Now, let's say you need to calculate the amount of snowfall for 4 inches of rain at 3 °F, so you will multiply 4 by 40, which is the snow coefficient for temperatures between 0-9 °F. Your answer is 160 inches.
So, at 3 °F, 4 inches of rain is equivalent to 160 inches of snow.

  • Inches of snow to rain

If you are like us and you wonder how much water you would be able to get from a bucketful of snow, all you need are some simple calculations in the same manner as we did to calculate inches of rain to snow.
For instance, for 12 inches of snowfall at a temperature of 16 °F, all you need to do is divide the amount of snow in inches by the snow coefficient, which in this case is 20. The result is 0.6 inches of rain.
Whether you need to calculate inches of rain to snow or inches of snow to rain, the actual rain to snow ratio remains unchanged. The only thing that changes is you either multiply the rain and snow coefficient or divide them by each other.

(Video) Liquid To Snow Conversion Calculator iPhone App - Rain to Snow Ratio Sugar Coded Appvertisement

Is it going to rain or snow today?

Checking the weather report near Christmas 🎄 can be stressful as so many people are anxious about the weather on Christmas Day. Many people are asking: "Mommy, is it going to rain or snow today?", "Are we going to have a white Christmas?" or "Am I gonna be able to make an even bigger snowman then last year?".
Rain to snow conversion is more than just a matter of mere calculations. It also helps in precipitation forecasts.
If the atmospheric temperature is above or expected to be above freezing point, then it will likely rain, but if the temperature is expected to be below the freezing point, then snowfall can be forecast.

Want to get into the chill spirit of winter? Wish to discover some more science?

We've got you covered!

Try the white Christmas calculator or the freezing point depression calculator. 🎄

(Video) Snow Load Calculation - How to Determine Snow Loads Including Snow Drift

What temperature does rain turn to snow?

If you actually think about it, rain doesn't turn to snow. They both are different forms of precipitation that require different circumstances to form, and if rain were to freeze, it would become ice and not snow.
When we ask at what temperature does rain turn to snow, what we actually mean is how cold does our atmospheric temperature have to be so that the snowflake falling from the sky maintains its form and reaches the ground? Because, in certain cases, the atmospheric temperature at the clouds is cold enough to produce snow, but as it moves down towards the ground where the temperature is higher in comparison, it melts and reaches us in the form of rain.

How many inches of snow is equal to one inch of rain?

After enjoying a play in the snow, making an adorable snowman ☃️, skiing down a slope, and throwing snowballs at each other, you might look around and wonder, wow, if I collected all this snow and melted it, how much water would that be? To find the amount of water in snow you need to follow mostly the same process as the rain-to snow conversion. So you can follow the steps explained in the rain to snow conversion section, or if you are in a hurry, use our rain to snow calculator, enter any amount of rain, select the temperature, and you have your answer.

The purpose of calculating the number of inches of snow to rain is also helpful in determining the amount of water that is eventually returned to our natural water reservoirs, like lakes and ponds in the area.

Hungry for knowledge? Take a look at our pond calculator to learn something new!

(Video) Measuring rainfall


At what temperature does rain turn to snow?

Rain turns to snow at around 27 - 32 °F. The atmospheric temperature has to be at or below freezing.

How many inches of snow is equal to one inch of rain?

If we ignore other factors, then one inch of snow is approximately equal to 10 -12 inches of snow. So the rain to snow ratio would be written as 1:10 or 1:12.
This ratio can vary from 2 - 3 inches of solid/hard ice like snow to 40 - 50 inches of dry, powdery snow, depending on the weather conditions.

(Video) Snow To Rain Ratio

Is it going to rain or snow today?

If you are one of those people who stand at their window almost every day in December wondering, "Is it going to rain or snow today" then all you need to know is the temperature of your area.
If the temperature is above freezing point, then there is a chance of rain, and if the temperature is below freezing point, it is more likely to snow.


How do you convert rain to snowfall? ›

Most weather services say that, on average, the amount of snow is 10 times the rainfall volume, that is, 1 inch of rain is equivalent to 10 inches of snowfall. If the snow is dense and molecules are tightly packed, then the ratio is 1:8.

What does 1 inch of snow equal in rain? ›

How many inches of snow equals one inch of rain? On average, thirteen inches of snow equals one inch of rain in the US, although this ratio can vary from two inches for sleet to nearly fifty inches for very dry, powdery snow under certain conditions.

What is 2 inches of rain equivalent to in snow? ›

The baseline ratio of rain to snow is 1 inch of rain equals 10 inches of snow. For example, to calculate the snowfall equivalent of 3 inches of rain, multiply 3 by 10 to obtain 30 inches of snow as the baseline conversion.

How many mm of rain equals snow? ›

The accepted average ratio is 10 to 1. This baseline conversion applies for snow falling at temperatures near freezing, between – 3 and 2 C.

How much snow does it take to make 1 inch of water? ›

An old rule of thumb was that for every 10 inches of snow, there would be 1 inch of water (10:1).

Do rain drops start as snow? ›

Most rain actually begins as snow high in the clouds. As the snowflakes fall through warmer air, they become raindrops. Particles of dust or smoke in the atmosphere are essential for precipitation. These particles, called “condensation nuclei,” provide a surface for water vapor to condense upon.

How much does 12 inches of wet snow weigh? ›

To put this into numbers, let's take a 1,500 square foot house when 12 inches of snow falls. Fluffy snow would weigh about 4 pounds per square foot. That would equal over 6,200 pounds of snow on the roof. Heavier, wet snow would weigh about 12.5 pounds per square foot and put 18,000 pounds on top of the house.

How much rain equivalent is 6 inches of snow? ›

Better and more recent research has now adjusted that rule of thumb to about a foot of snow to 1 inch of rain. So that 6 inches that just fell, if it were a pretty typical snowfall, would have been about a half-inch of rain.

How do you calculate snow ratio? ›

To calculate the snow-to-liquid ratio, divide the amount of snow by the depth of water you would measure if you melted the snow into liquid. A ratio of 10 inches of snow to 1 inch of liquid (10-to-1) will be fun but feel a little heavy.

Is a 1/4 inch of rain a lot? ›

1/4 (0.25) of an inch of rain – A light rain for 2-3 hours, moderate rain for 30-60 minutes or heavy rain for 15 minutes. There would be many puddles on the ground and they would not disappear easily.

How much water is in 5 inches of snow? ›

Heavy, wet snow has a very high water content and 4 or 5 inches of heavy, wet snow can contain about one inch of water, while it may take 20 inches of dry, powdery snow to equal one inch of water. The 10=1 equation also assumes a 'perfect' snowmelt without evaporation or other losses.

How much water is 2 inches snow? ›

The 'snow to ice ratio' or Snow Ratio expresses how much volume of snow you get for a given volume of water. Typically a ratio of 10:1 (ten to one) means that every 10 inches of snowfall equals one inch of liquid water.

Is 1 inch of rain equal to 10 inches of snow? ›

How much snow does it take to equal an inch of rain? This varies depending on the type of snow, but to make 1 inch of water (rain), you need 10 inches of average snow, 4 to 5 inches of wet snow, or 15 inches of powdery snow.

How Much Is 10mm of rain in snow? ›

This general rule of thumb is dependent on the temperature & the shape/size of the snow. My general rule of thumb is 10:1 +- 50%. So in a much colder place overseas, 10mm of precipitation can get you 15cm+ of very light powder.

Is 15 mm of rain a lot? ›

15 mm of precipitation means 15 kilograms of water per square meter of the Earth's surface, and that's quite a large amount — one and a half buckets of water. Given the fact that the Earth's surface is uneven, precipitation flow into low-lying areas, forming turbulent streams and deep puddles.

How heavy is 5 inches snow? ›

If it snows 5” of wet snow, it will weigh about 12.5 pounds. With this information, you're now likely wondering about the weight of snow load on your roof. There is a calculation for this, too!

How long does it take to melt 3 inches of snow? ›

Three days of temperatures at 50 degrees can melt 2 to 4 inches of snow. If temps fall below freezing at night, the process will be slower. The amount of moisture in the air can accelerate the melting process, while wind will carry away the moisture and preserve the snow pack.

How much water will 10 inches of snow melt down to? ›

Answer: There's a rule of thumb that 10 inches of snow equals 1 inch of water, but it really depends on how wet the snow is, and that depends on temperature. Drier snow can be expected at lower temperatures and vice versa.

What is rain snow called? ›

Sleet (Ice Pellets) are frozen raindrops that strike the earth's surface. In a sleet situation the precipitation aloft when it is first generated will be snow.

Why do rain drops not hurt? ›

Hint When raindrops are falling they experience air resistance and force due to this balances gravity, so acceleration stops while raindrops attain constant terminal velocity which is not high enough to cause damage. Damage is caused by sudden change in momentum.

Is Wet snow a thing? ›

Wet snow is caused by air temperatures near the surface being just above freezing, so snowflakes slightly melt before hitting the surface causing wet snow to accumulate. Wet snow causes a slushy mess on the roads, weighs down powerlines, trees and also has a better chance of forming an icy layer.

Should I shovel snow off my roof? ›

Whether a large amount of snow has accumulated over days and weeks, or you just experienced a good old-fashioned blizzard, consider removing snow from your roof. Generally speaking, after roughly 15 cm (6 inches) of snowfall, your roof should be cleared. And the sooner you do it, the better.

How much is 1 foot of snow? ›

As a rule of thumb, snow weighs approximately 20 pounds per cubic foot, or 1.25 pounds per inch of depth.

What roof pitch is best for snow? ›

Roofs in snowy climates should have a slope of at least a 10-degree pitch minimum. A steeper angled roof sheds the snow more quickly. While the angle of the roof helps shed snow, adding too many angles to the roof for a more aesthetic effect could cause structural problems with snow shedding in the wintertime.

Is it true that snow falls at 1 to 6 feet per second? ›

Snow falls consistently.

Snowflakes fall at a rate of 1-6 feet per second, in all conditions. Even during high storms, snowflakes still fall in that range of speed.

How many inches is considered heavy snow? ›

Heavy Snow Warning

Issued by the National Weather Service when snowfall of 6 inches (15 cm) or more in 12 hours or 8 inches (20 cm) or more in 24 hours is imminent or occurring.

How much is 1 inch of rain? ›

An inch of rain is exactly that, water that is one inch deep. Per the USGS Rainfall Calculator, one inch of rainfall equals 6 gallons of water per square yard or 27,154 gallons of water per acre!

What does a 40% chance of snow mean? ›

A 40 percent chance of snow means the forecaster believes you will experience snow 4 out of every 10 times you hear such a forecast (assuming the forecasts verify perfectly). However, forecasters use probabilities to describe all kinds of weather situations.

What does a 30% chance of snow actually mean? ›

Wrong. It also doesn't mean it will rain 30% of the day. The percent chance of rain (or snow or thunderstorms) is called the “Probability of Precipitation,” or PoP. The figure refers to the chance that the forecast area will see at least 0.01 inches of rain, according to the National Weather Service.

What does a 30% chance of snow mean? ›

2. The areal coverage of that precipitation over the entire forecast area. Therefore a 30-percent chance of snow showers could mean confidence is high that the showers will occur, but maybe not over the entire forecast area.

What is considered heavy rain? ›

Moderate rain — when the precipitation rate is between 2.5 mm (0.098 in) – 7.6 mm (0.30 in) or 10 mm (0.39 in) per hour. Heavy rain — when the precipitation rate is > 7.6 mm (0.30 in) per hour, or between 10 mm (0.39 in) and 50 mm (2.0 in) per hour.

Can 1 inch of rain cause flooding? ›

Flooding is an overflowing of water onto land that is normally dry. Floods can happen during heavy rains, when ocean waves come on shore, when snow melts quickly, or when dams or levees break. Damaging flooding may happen with only a few inches of water, or it may cover a house to the rooftop.

How much weight is 10 inches of snow? ›

Ten inches of fresh snow equates to about five pounds per square foot, which means your roof likely can support four feet of fresh snow.

How much snow does it take to make 1 gallon of water? ›

One gallon (US measure) of water weighs approximately 8.3 pounds. If the snow in your one gallon container weighs four pounds then the water content of the snow is almost 50 percent which means it will take two gallons of snow to make one gallon of water.

How deep can you sink in snow? ›

First, the age of the snow will increase or decrease how far you sink. A newly fallen field is going to be trouble to walk through because each step will be a maximum sink. This may be as high as 6 to 12 inches, depending on the snow and other variables! In a more packed snow, you may sink 6 to 8 inches.

Is half an inch of snow an hour a lot? ›

Snow will often accumulate at a rate of 0.5 inches an hour. Snow falling at over 1 inch per hour will lead to rapid disruption.

Why is wet snow heavier? ›

One inch of wet snow can contain 2 to 3 times more water than one inch of dry snow, making it that much heavier. This makes it difficult to shovel and the weight of the wet snow can snap tree limbs and power lines causing power outages.

Does snow get heavier when it warms up? ›

Snow density is a function of temperature, wind exposure, and time. Snow density increases over time as the snow experiences more changes in temperature and wind. Warmer temperatures lead to higher (and heavier) moisture content; the water may re-freeze into ice when the temperature drops.

Is 3 inches of snow the same as 3 inches of water? ›

The baseline ratio of rain to snow is 1 inch of rain equals 10 inches of snow. For example, to calculate the snowfall equivalent of 3 inches of rain, multiply 3 by 10 to obtain 30 inches of snow as the baseline conversion. It all depends on how wet is the snow and what is the temperature.

What does 12 inch rain mean? ›

One inch of rain over 1,000 square feet of surface is 623 gallons of water. The roof of a house averages 3,000 square feet, therefore 1 inch of rain on a roof produces 1,869 gallons of water. Multiply that by 12 inches of rain and you get 22,000 gallons of water running off my roof in the last couple of weeks.

What does it mean 5 inches of rain? ›

The "inches of rain" is the depth that the water would be if it fell uniformly across a flat surface. So, 5 inches of rain would fill your yard to a depth of 5 inches, assuming it didn't run off or soak in, your roof isn't also draining into the yard, etc.

What is 1mm of rain in snow? ›

One millimetre of rain corresponds to 1 litre per square metre of water on the surface, or approximately 10 millimetres of snow.

Is 5 to 10 mm a lot of rain? ›

Heavy rain: Greater than 4 mm per hour, but less than 8 mm per hour. Very heavy rain: Greater than 8 mm per hour. Slight shower: Less than 2 mm per hour. Moderate shower: Greater than 2 mm, but less than 10 mm per hour.

Is 20 millimeters of rain a lot? ›

A Heavy Precipitation Day (HPD) is a day on which at least a total of 10 mm (or 20 mm) of rain or frozen precipitation falls. Frozen precipitation is measured according to its liquid equivalent: 10 cm of snow is usually about 10 mm of precipitation.

What does 80% chance of rain mean? ›

An “80% chance of rain” means that there is an 80% chance that rain will fall somewhere within the forecasted area. Rain refers to 0.01 inch or more.

What does 90% of rain mean? ›

When we say there's a "30% chance of rain," what does it really mean? When we give a percent chance of rain, we as meteorologists know that it will rain at some point that day. The percent is the amount of area coverage or people that will see rain for sure.

What does 40% rain mean? ›

If a forecast for a given county says that there is a 40% chance of rain this afternoon, then there is a 40% chance of rain at any point in the county from noon to 6 p.m. local time.

What temperature does rain turn to snow Celsius? ›

In order for the surface precipitation type to be snow, the atmospheric temperature (dashed red line in Figure 1) must be at or below 32°F (0°C) to ensure that no melting occurs.

How is snow formed step by step? ›

Snow forms when tiny ice crystals in clouds stick together to become snowflakes. If enough crystals stick together, they'll become heavy enough to fall to the ground. Snowflakes that descend through moist air that is slightly warmer than 0 °C will melt around the edges and stick together to produce big flakes.

How do they calculate inches of snow? ›

Snow Depth (total depth of snow on the ground) is reported to the nearest WHOLE INCH (such as 11").
How to Measure:
  1. Push the yardstick straight into the snow, perpendicular to the ground, until the yardstick reaches the snow board.
  2. Record the measurement to the nearest tenth of an inch; e.g. 3.3 inches.

Can it snow without being 32 degrees? ›

Snow is a form of ice crystal, and, although it can fall through a layer of air that is above freezing, it does require temperatures below 32 degrees to form in the sky.

Can it snow at 20 degrees? ›

Snow can occur even at incredibly low temperatures, as long as there is some source of moisture and some way to lift or cool the air. It is true, however, that most heavy snowfalls occur when there is relatively warm air near the ground—typically -9°C (15°F) or warmer—since warmer air can hold more water vapor.

Can snow happen at 34 degrees? ›


If the above-freezing layer of air is limited to near the surface, the snow won't have much time to melt before it reaches the ground, allowing it to keep snowing even if your outside thermometer says 33, 34, or 35 degrees.

Can it be too cold to snow? ›

Nope. In the Earth's atmosphere, it can never be too cold to snow. All that is necessary is water vapor in the air–and some is always present, even at very low temperatures–and a mechanism to chill the air below its saturation temperature.

Why is it warm when it snows? ›

The weather becomes warm when it snows as an enormous amount of heat energy is released when ice is formed, which makes the weather warm.

Does it snow in Africa? ›

Additionally, snow regularly falls in the Atlas Mountains in the Maghreb. Snowfall is also a regular occurrence at Mount Kenya and Mount Kilimanjaro in Tanzania. There have been permanent glaciers on the Rwenzori Mountains, on the border of Uganda and the Democratic Republic of the Congo.


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