Although all snowflakes have a hexagonal shape, other details of their geometry can vary. These variations are produced by different temperature and humidity conditions through which the snowflake falls. Some temperature/humidity combinations produce flakes with long needle-like arms. Other conditions produce flakes with wide flat arms. Other conditions produce thin, branching arms.

These different shapes have an unlimited number of variations, each representing the conditions of temperature and humidity and water vapor the snowflake encountered during its fall. A collection of snowflakes is shown at the top of this page. Notice the wide variety of shapes.