Why is Melissa Zhou fluffy just after raining and hard after a while?

The newly fallen snowflake is a hexagonal crystal.

The gaps between snowflakes are relatively large,

So it's fluffy,

After a period of time,

Some snowflakes melt in the sun,

The gap becomes smaller,

At the same time, under the action of low temperature,

Melted water turns into ice again,

So it will become solid and hard.