Science
How do snowflakes form?
A snowflake forms when water vapor in a cold cloud freezes directly onto a tiny particle, building an ice crystal. As it falls through changing temperature and humidity, it grows six symmetric arms — which is why no two snowflakes are quite alike.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how snowflakes works.
Step by step
- 1Water vapor freezes onto a tiny dust particle in clouds.
- 2Ice crystals grow with six-fold symmetry.
- 3Their shape depends on temperature and humidity as they fall.
- 4Tiny differences make each snowflake unique.
Frequently asked questions
- How do snowflakes form?
- Water vapor freezes onto a particle in a cold cloud, growing into a symmetric six-armed ice crystal.
- Why do snowflakes have six sides?
- Water molecules bond in a hexagonal pattern when they freeze, giving crystals six-fold symmetry.
- Are all snowflakes really different?
- Essentially yes — each follows a slightly different path, so their detailed shapes are virtually never identical.