Here are the lowest temperatures across Colorado on Tuesday morning, according to the National Weather Service.

Are you ready for the coming arctic storm? Here’s the latest Colorado weather forecast and everything else you need to know ahead of extreme cold.

Still, several Colorado school districts will start late on Tuesday as the state waits out the last of subzero temperatures. Denver, Jefferson County, Aurora, Littleton, St. Vrain Valley and Weld, among others, are all on a two-hour delay.

More than 500 flights were delayed or canceled at Denver International Airport on Monday as a polar vortex continued to freeze metro Denver.

More extremely cold temperatures and wind chills are still to come. Another wave of snow comes late Sunday.

The polar vortex's blast of Arctic air from Canada brought the season's coldest weather to the majority of U.S. The vortex is forecast to provide frigid weather as it continues to bring sub-zero temperatures to the Midwest, Mid-Atlantic and plunge deep into the South.

The most unusually cold air in the Northern Hemisphere will be over the United States early next week, bringing dangerously frigid conditions.

According to the NWS, the Arctic polar vortex is a powerful band of west-to-east winds that develops in the stratosphere, about 10 to 30 miles above the North Pole, during the winter season. It is always present near the poles, though it weakens during summer and intensifies in winter.

Some areas of the U.S. may see temperatures as low as -20 or -30 degrees early next week as arctic air from Siberia rolls in.

Colorado will see its coldest temperatures of the winter as a mass of cold air descends on the state from the Artic. But despite the bitter cold, this weather event is not a polar vortex.

The Arctic air mass will be in Colorado Friday afternoon, but the effects of the polar vortex won't be fully felt until after the sun goes down. Snow will come into the state's high country in two ...

More than 400 flights were delayed or canceled at Denver International Airport on Monday as a polar vortex continued to freeze Colorado. There were 394 delayed and 27 canceled flights as of 12:40 p.m.