Needle ice

Have you ever seen ice that looks like needles sticking up out of the ground? That's something called "needle ice"! It usually happens when the ground temperature is above freezing during the day but drops below freezing at night.

When soil is really wet, it can freeze when it gets cold outside. But sometimes, water inside the soil doesn't freeze into solid ice. Instead, it stays as a liquid and seeps up towards the surface. When the temperature above the soil is below freezing, the water that has seeped up forms little crystal formations that look like needles.

These "needles" can grow up to several inches long and poke up out of the ground. It's a cool and pretty sight during wintertime, but it can also be dangerous if people or animals slip on it. So if you see needle ice outside, make sure to walk carefully!