National Weather Service

What Is Rime Ice? See the Cool Formations Popping Up in the Midwest

These aren't your average ice formations

Ice forming on trees amid heavy snowfall in Duluth, Minnesota.
Joe Brooks

Wintertime ice can certainly be a pain for drivers and joggers, but it can also be quite stunning at times.

In recent days, fascinating ice formations have been popping up in the Midwest, and they've been captivating local onlookers and the Twitter community alike.

The breathtaking phenomenon is called rime ice and it looks a lot different than the icicles you're used to seeing hanging from houses and trees. Rime ice is kind of similar in appearance to the spiky fuzz you might find on caterpillars or a cartoon monster, and it comes across as more cute than dangerous.

Never heard of it before? Neither had we. But here's how the National Weather Service officially defines rime ice: "An opaque coating of tiny, white, granular ice particles caused by the rapid freezing of supercooled water droplets on impact with an object."

Minnesota residents have been lucky enough to spot the spiky formations across the state and have been sharing the stunning photos on Twitter this past week.

Freezing fog and bone-chilling temperatures combined forces to create the winter wonderland scene, and local meteorologist Joe Brooks shared the following series of photos on his Twitter account.

The weather service in Duluth, Minnesota also posted this awesome time-lapse video showing how rime ice forms.

According to the weather service, rime ice is made up of ice crystals that lock together and often appears in tree branches. It's also a bit different than frost.

"In the case of rime, the object and the air are both below freezing and liquid drops (e.g. fog) must be present. For frost, the object itself must be below freezing but the air can be above freezing. Also, water vapor (not droplets) are the source of moisture, so frost forms on clear cold nights," the organization wrote on its website.

Twitter user Wes Saunders-Pearce called the magical ice "just stunning" on his account.

Rime ice is pretty unique looking.
Wes Saunders-Pearce

Saunders-Pearce shared both a close-up and a far look at the whimsical ice in photos taken in Maplewood, Minnesota on Thursday.

This is definitely a winter wonderland.
Wes Saunders-Pearce

Minnesota wasn't the only state waking up to rime ice formations; the bizarre weather phenomenon appeared in Wisconsin too.

Much like Minnesotans, folks in Wisconsin were captivated by the rime ice and many Twitter users couldn't help but share photos from their own nature walks.

Captivating ice formations seem to pop up every winter and in 2019, parts of Niagara Falls appeared to be frozen solid.

In January 2019, ice and snow-covered branches near the brink of the Horseshoe Falls, due to subzero temperatures in Niagara Falls. 
LARS HAGBERG/AFP via Getty Images

The falls themselves weren't actually frozen solid and they didn't stop flowing. But the water's mist and some areas of slow-moving water were indeed frozen, and it was a sight to be seen.

Isn't Mother Nature amazing?

This story first appeared on TODAY.com. More from TODAY:

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