MINNEAPOLIS (WCCO) — We all know Minnesota winters can be long and hard, but negative double digits is pretty cold, even for the heartiest Minnesotans.

So, that had David from Red Wing wanting to know: Where does this cold weather start?

Basically, the air circulates all over the world. In theory, you could balloon around the world if you caught the right winds.

But when that air passes through the Arctic Circle, it chills way down before making its way south.

“That’s where it really comes from, the Arctic,” said Pete Boulay, Minnesota’s assistant climatologist.

There are four air masses that affect the United States: the continental polar, the maritime polar, the maritime tropical and the continental tropical.

It’s the northern-most one, the continental polar, that was whopping the upper Midwest Wednesday.

In the wintertime, there is no sunlight to warm the air coming from way up North. The snow and ice also reflect what little heat there is and allow it to escape into space.

Depending on the jet stream, the air can cross over Siberia, Alaska, Northern Canada and even the North Pole before it makes its way south.

It can warm a good 30 degrees by the time it reaches Minnesota. It is rare for the arctic air to make it to Minnesota in the summer.

“In a typical winter, you’ll have the cold, and then you’ll have a little bit of a January thaw where you get a little taste of some other air mass other than the continental polar,” Boulay said.

The jet stream moves north enough in the summer to keep the arctic air closer to the Arctic Circle.

Heather Brown

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