Snowflakes come in 35 distinct shapes grouped into seven categories. An eighth category of frozen precipitation contains an additional four shapes, including hailstones and sleet particles.
Snowflakes form in clouds, when water vapor condenses, freezing into ice. The most basic snowflake shape is a hexagonal prism. These snowflakes have six sides connecting a top and bottom base and can either be tall, like a column, or flat, like a plate.
These shapes are highly dependent upon temperature and humidity, with more complex shapes forming when more moisture is in the air. Scientists have not yet figured out why temperature affects snowflake shape so significantly.
Snowflake experts, or crystallographers, have found that these 39 shapes can be further subdivided down into 121 subtypes.
To learn more about snow, crystallography, and meteorology, check out the following Science NetLinks resources:
- A Matter of Pattern (K-2)
- The Science of Weather (K-12)
- Water 3: Melting and Freezing (K-2)
- SnowCrystals.com (3-12)
- What Do Scientists Do? (6-8)
- Frosty the Snowman Meets His Demise (9-12)