How is Snow Formed

As a result of low temperatures and atmospheric moisture, snow forms as ice crystals.

Except for extreme southern states, winter in the United States means at least some snowfall. Rain and snow formation have a lot in common.

What is snow?

Snow is defined as the accumulation of small ice crystals, which occur at temperatures well below 0°C.

Snow is a form of frozen water that forms in the atmosphere, accumulates on the ground, and then melts, slides or sublimates away.

A snowstorm organizes and develops by consuming atmospheric moisture and cold air and taking on a variety of shapes. They may sinter, sublimate and freeze-thaw over time.

Snow-prone regions include the polar regions, mountainous regions worldwide, and the Northern Hemisphere, and it affects transportation, agriculture, and sports.

How does snow form?

Snow is formed when tiny ice crystals in clouds stick together to form snowflakes. If the air is moist, it will melt around the edges to form big flakes.

How cold does it have to be to snow?

When the air temperature is below 2 °C, snowfalls, but the air temperature around a snowflake is cooled as the snow melts.

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Facts for Kids

If it’s warmer than 2 °C, the snow will melt, creating sleet or rain.

‘Wet’ snow vs. ‘dry’ snow

How many ice crystals group together determines a snowflake’s size and composition.The ‘dry’ snow is ideal for snow sports, but the ‘wet’ snow is good for making snowmen.

Basic Conditions

Winter snowstorms are formed when warm, moist air rises from the Earth’s surface and collides with cold air or cools when moving up a mountain slope.

Water Droplet Formation

Clouds form when water vapor condenses around a solid surface. As the cloud rises, the condensation turns to ice, and snow crystals form.

Snow Crystal Formation

Snow crystals start to form in cold air when cloud temperatures reach about -10 degrees Celsius (14 degrees Fahrenheit). The snow crystals are symmetrical and grow by colliding with each other to form larger snow crystals that fall as they become heavy.

Variations in Snow Crystals

Snow crystal shapes depend on temperature. From 0 to -4 degrees Celsius, thin hexagonal plates form, hollow columns form at -6 to -10 degrees Celsius, and many snowflakes are larger than 1.3 centimeters.


Snowflakes form when tiny ice crystals in clouds stick together to form big flakes.

They melt if the temperature is warmer than 2°C and falls as sleet. Dry, cool air causes snowflakes to break up into small, powdery pieces.

Highest Temperature for Snow

At 50 degrees, snow can fall. Snow at temperatures greater than 45 degrees is rare in northern parts of the United States.

How is Snow Formed on Mountains

At a higher altitude, the atmosphere becomes thinner. Air pressure decreases with altitude. Warm air rises, but as it rises, it expands and cools. The more moisture there is, the more rain and snow will fall, especially at the top of a mountain.

Why is there Snow on Mountains in the Summer

In the summer, mountains have snow because it hasn’t melted yet.

When you go higher, the temperature decreases and the earth stores heat from the sun, so the less Earth around you, the slower the snow melts.

The sun and air temperatures will warm the snow, and the volume of snow will take longer to melt.

Which Mountains are Covered with Snow all Year

Mt. Washington gets hit by a lot of snow, but it doesn’t stick around long, and the snow gets blown off into the surrounding ravines.

  • Chamonix, France
  • Nagano, Japan
  • Kirkwood Mountain, California
  • Alyeska, Alaska
  • Alta Ski Area, Utah
  • Mt. Fidelity, Glacier National Park, BC, Canada
  • Niseko, Japan

Why is There Snow on Top of Mountains Above Clouds

Snow falls from storms onto the summit. Even though only a little snow actually falls directly on the summit due to harsh conditions, this is referred to as “storm snow.”.

Even if a particular storm does not reach high enough to produce snow around the summit, strong winds blow snow around.

This is known as “wind transported snow.” Strong winds blowing snow from Everest have been photographed many times.