“We’re making a snowman as big as we can! Put the snowball in snow in the sun to make the snow stick. The sunny snow is shiny. The shininess makes the snow stick,” explained students at North Branch Nature Center Forest Preschool.
You can tell the quality of snowball snow through the squeeze test: pack a snowball tightly and observe. If water is released, the snow is too wet (it will turn into a chunk of ice and could hurt someone). If you can’t form a snowball, the snow is too dry. If you can pack together a snowball without water being released, the sticky state is just right!
The pressure (not the heat) from your hands packing the snowball can melt some snow when temperatures are just below freezing. As you release the snowball, that liquid water refreezes and welds the snowflakes together into a snowball. If the temperature is too cold, you won’t be able to pack with enough pressure to form this snow glue.
Surface moisture is the most important factor for snowballs. So if the snow is too dry, finding snow that has melted a bit in the sun or from the heat of a building is a good place to start!