How does snow form?

No snowflake is precisely the same as the other. Yet, they all fall into one of 35 different shapes, according to researchers. But how exactly do they form? ❄️

Stars, plates, columns…

Snowflakes can take many shapes. They’re formed in high-altitude clouds if their temperature is below zero and if the atmosphere contains water vapor and dust particles. The water vapor condenses around them until it forms hexagonal ice crystals. Their tips grow depending on temperature and humidity. Once the snowflake measures a few millimeters, its weight makes it fall: it’s snowing.