Polar vortex brings extreme cold to much of US, warmth expected next week

The polar vortex has brought extreme cold to much of the United States, making it colder than Greenland and even Mars. On Wednesday, the average low temperature in the continental U.S. was 13.7 degrees Fahrenheit. A significant warm-up is expected early next week, with temperatures in some areas rising by 90 degrees. However, another cold wave is predicted to return in early March. This winter has seen the polar vortex stretch multiple times, causing record low temperatures in places like North Dakota. Meteorologists note that the current cold outbreak is among the most severe for this time of year.