Extreme cold snaps: Why temperatures still plummet to dangerous levels even as the planet warms

(CNN) -- Even as the world smashes through one all-time heat record after another and speeds towards critical warming thresholds, brutal waves of deadly cold can still arrive in bomb cyclones that bring icy weather and deep snow -- and add fuel for those who deny the climate crisis is real or significant.

But some scientists say that climate change -- and more specifically rapid warming in the Arctic -- may actually be increasing the likelihood that frigid, polar air can dive south.

Look no further than the heavily populated US Northeast this weekend to see a real-time example of the long-term warming trend being interrupted by tremendous, record-setting cold.

Last month will be remembered for the winter-that-wasn't in the region -- ranking as the warmest January on record for nearly all Northeast cities. It was the first month in New York City that temperatures ranked above-average every single day, and first time the month ended without measurable snowfall in the city.

But the weather pendulum swings hard to the other extreme this weekend when record warmth will become record cold, with dozens of low temperature milestones predicted. The wind chill is expected to plunge to dangerous levels of minus 30 degrees Fahrenheit (minus 34 Celsius) for millions on Saturday.

So what's going on?

Extreme cold

While winters are becoming warmer overall and warm records outpace cold, this January brought a brutal cold snap deep into parts of Asia.

Temperatures in the city of Mohe in northern China plummeted to minus 53 degrees Celsius (minus 63.4 degrees Fahrenheit), the lowest temperature the country has ever recorded.

Fierce cold and record amounts of heavy snow in Japan killed at least four people in what the country's Chief Cabinet Secretary Hirokazu Matsuno called a "once-in-a-decade cold snap."

Low temperature records also fell in several places in South Korea.

"Cold air from the North Pole has reached South Korea directly," after traveling through Russia and China, Korea Meteorological Administration spokesperson Woo Jin-kyu told CNN.

More than 150 people died in Afghanistan as temperatures reached lows of minus 28 degrees Celsius (minus 18 degrees Fahrenheit), in what has so far been one of the country's harshest winters.

And the world's coldest city, Yakutsk in eastern Siberia, saw temperatures reach minus 62.7 degrees Celsius (minus 80.9 degrees Fahrenheit) -- the lowest in more than two decades according to meteorologists.

Extreme winter weather is now shifting to the US, with dangerously cold Arctic air pushing southwards, sweeping across many parts of the country and quickly dispensing with what had been a mild January.