Why don't snowflakes stick together as they fall?

Snowflakes form inside clouds as tiny ice crystals. Each snowflake has its own special shape, with pointy edges and six sides. Unless those pointy edges lock together, the flakes don't stick easily.

When they fall through the air, the air is usually cold and dry. This keeps the surface of the snowflakes rough and frozen, not sticky. Since there's no wet, sticky surface, the flakes just slide past each other.

But sometimes the air is a bit warmer, close to zero degrees. Then the edges of the snowflakes start to melt just a little. The wet edges stick together and form big clumps of snow. These are called 'snow clumps,' and they fall from the sky like giant white lumps.

So snowflakes don't always stay apart! Depending on the temperature, they sometimes drift down alone, and sometimes join together in clumps.