I'll admit that this has more to do with chemistry than physics, but really when it boils down to it, everything is physics.
To celebrate that the snow is over (hopefully), let's watch how it grows in the first place
Quite beautiful, isn't it? Especially with the music and all. So why do they grow that way? Well, it all has to do with the formation of hydrogen bonds. Usually, when water goes below the freezing temperature, the bonds form a nice crystal-lattice structure that leads to regular ice. However, due to the changing temperatures within clouds and the fact that hydrogen bonds form hexagonal structures, snowflakes happen. They start as hexagonal prisms that slowly form arms and branches while transitioning from temperature to temperature, resulting in the special snowflakes we all know and love - as long as they stay in the winter where they should be
https://www.youtube.com/watch?v=VYrF3sFBY20's a video that shows it nicely