- Generally, six-sided hexagonal crystals are shaped in high clouds.
- Needles or flat six-sided crystals are shaped in middle height cloud.
- A wide variety of six-sided shapes are formed in low clouds.
- Colder temperatures produce snowflakes with sharper tips on the sides of the crystals and may lead to branching of the snowflake arms (dendrites).
- Snowflakes that grow under warmer conditions grow more slowly, resulting in smoother, less intricate shapes.
Why are snowflakes symmetrical (same on all sides)? Actually, not all snowflakes are symmetrical. Several things can distort the shape of a snowflake including uneven temperatures, dirt, and other factors But in most cases snowflakes form in an orderly and symmetrical manner. This is because when water freezes, the shape of the ice crystal reflects the internal order of the water molecules. When molecules freeze into the solid state, the bonds or connections between the water molecules are very weak. During crystallization, the water molecules align themselves to maximize these bonds as much as possible. Consequently, water molecules arrange themselves in a chemically predetermined manner that tends to maintain symmetry.