The polar vortex returns. Here’s how cold it’ll get where you are.

A January thaw that brought widespread record warmth to the United States is coming to an end.

It will be replaced by the familiar polar vortex pattern that caused below-average temperatures in the Midwest and East last month – with lobes of Arctic air frequently blowing in during the second half of January.

The first cold wave will reach the East Coast on Thursday, followed by another surge of frigid air this weekend and a third next week, which may be the most severe of the trio.

Not even Florida will be spared. There, freezing temperatures are expected Friday as cold air plunges across the Gulf of Mexico toward Cuba and Mexico’s Yucatán Peninsula.

As these chilly conditions settle in one part of the country, unseasonably warm conditions will again develop in the West, where a snow drought is ongoing, as well as across western Canada and Alaska.

How cold it will get and how long it will last

Over the next two weeks, waves of frigid air are forecast to spill into the central and eastern United States.

The first wave will track across the Eastern Seaboard from Thursday into Friday, causing temperatures to dive 10 to 20 degrees below average.

In D.C., high temperatures on Thursday will struggle to reach freezing. In Florida, where freeze watches are in effect, a record low of 29 degrees is forecast in Lakeland, east of Tampa, on Friday morning.

Despite the chill, only a handful of low-temperature records may be neared or broken, which illustrates how it’s becoming more challenging to break such records amid a warming climate.

From Wednesday into Thursday, accumulating snow will accompany the cold air arriving in the Great Lakes, Appalachians, western and central New York, and northern New England. Winter weather advisories are in effect in parts of these regions.

More flakes will fly across the Midwest and East this weekend into next week, ushering the second and third waves of the polar plunge – but a big winter storm is not expected.

The third wave is looking to be the harshest, with the potential for widespread subzero temperatures affecting around 40 million people from Minnesota to Maine next week. In the Upper Midwest, low temperatures appear likely to dip into the minus-10s and -20s and possibly the minus-30s in a coldest-case scenario.

There are signs that this spell of frigid conditions will last through the end of January – and could link up with moisture to form a more potent winter storm or two toward the end of the month.

Why is it getting cold again?

The easy answer is that it’s January.

However, there’s more to it than that. After an unusually early disruption to the polar vortex in late November, that ring of frigid conditions that typically sits above the North Pole never fully recovered.

The disturbed vortex has instead been located farther south than normal across Canada, continuously exposing a section of the northern United States to its cold wrath.

But temperatures haven’t been below-average everywhere. Some far-flung places have experienced well-above-average temperatures this winter as the polar vortex slid south, including Greenland, northeastern Russia and Alaska’s Aleutian Islands.

Kullorsuaq, a settlement in western Greenland, has experienced temperatures this winter that are 24 degrees above average, making it the most anomalously warm place in the Northern Hemisphere.

Why it hasn’t been that cold so far this winter

Although the polar vortex has been frequently featured in weather headlines, this winter hasn’t been that cold across the United States compared to years past.

In fact, it’s quite the opposite – the country is experiencing one of its warmest winters.

That’s because the West has been so unseasonably warm, offsetting the chill in the Midwest and Northeast, with six states running at least 8 degrees above average since the start of December.

The five warmest states, compared to average, have been Wyoming, Colorado, Utah, Idaho and Nebraska, while Vermont, New Hampshire, New Jersey, Maine and Rhode Island have been coldest.

This nationwide temperature divide will continue, as high temperatures near Los Angeles rise well into the 80s in the days ahead – more typical of summer.