Parts of Pennsylvania and New Jersey saw giant icicles form in mid-February.
They formed on gutters and around doorways.
Then, they started melting and falling off, despite the weather being only a few degrees above freezing.
It goes to show you the power of the sun beating down on them.
It's a lot like your car in the summer: it's always much warmer inside it than outside it on a hot day. That's because the sun beats down on the car, warming the inside of it. All that warmed up air gets trapped inside the car.
As for icicles, you'll see water drops drip off of them as they melt.
The water drops will be round.
Those circular drops are actually what a raindrop looks like. You'll often hear that raindrops are tear shaped, but that's not true.
Raindrops are usually spheres.
But, if a raindrop is big and if it falls through a lot of air, it will start looking like the top half of a burger bun. That's because air pushes up on the bottom of the round raindrop as it falls, flattening out the bottom.
A bunch of tiny circular water drops floating in the air make up fog. Fog is just a cloud near or at the ground.
In the winter, we'll sometimes see fog on cold mornings. This happened last Sunday.
When fog is down at the ground and temperatures are below freezing, you'll have freezing fog.
This means the tiny, circular water drops making up the fog instantly freeze when they hit something. If they hit something with frost or snow on it, they'll make a textured ice, called rime.
In this picture from Mount Washington, New Hampshire, the guys having some fun in alien costumes are pointing out the textured snow caused by the fog, which you see in the background, freezing on contact with the snow on the sign.
When the water drops in freezing fog hit something cold that doesn't have snow or ice on it, they freeze into ice.
Last Sunday, the freezing fog didn't make it all the way down to the ground. It stayed up in the sky, just above the ground.
This lead to the air at the ground being pretty humid despite temperatures below freezing.
As that humid air ran into tree branches, the moisture in the air instantly turned into tiny pieces of ice. Going from the gas form of water to the solid form creates a special kind of frost that looks fuzzy.
As more humid air hits this frost, this frost will grow outward, looking even fuzzier.