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This is why no 2 snowflakes are alike

What form a snowflake takes depends on the temperature and the amount of moisture in the cloud when they are forming.

By: Katie McGraw

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A snowflake begins to form when an extremely cold water droplet freezes onto a pollen or dust particle in the sky. This creates an ice crystal. The way that ice crystals join together gives every snowflake a unique design.

They form seven basic shapes: stars, needles, dendrites (having branches), plates, columns, columns capped with plates, or irregular due to damage.

But did you know that no two snowflakes are exactly alike?

This is because individual snowflakes all follow slightly different paths from the sky to the ground and encounter different atmospheric conditions along the way. Therefore, they all tend to look unique, resembling everything from prisms and needles to the familiar lacy pattern.

Ultimately, it is the temperature and humidity at which a crystal forms that determines the basic shape of the ice crystal. A crystal might begin to grow arms in one manner, and then minutes or even seconds later, slight changes in the surrounding temperature or humidity cause the crystal to grow in another way.

Thus, we see long needle-like crystals at 23 degrees and flat plate-like crystals at 5 degrees. More complex snowflakes are usually formed during warmer and wet conditions. Snowflakes formed in drier and colder conditions have a simple shape.

Below is a chart that explains the different types of ice crystals. Temperatures are colder from left to right, and moisture increases from bottom to top.