The lower 48 saw its coldest temperature so far this winter season: A biting -50 degree reading in Colorado.

The temperature was measured at the Antero Reservoir in Colorado on Wednesday morning. 

What You Need To Know

  • The temperature fell to -50F in Colorado Wednesday morning

  • Antero Reservoir sits in a bowl at about 9,000 feet in elevation

  • Cold air drains into the reservoir and is known for extreme cold

  • It's the 4th-coldest temperature ever measured at the reservoir

It's not a temperature that happens every year in the contiguous United States. In fact, you have to go back to February 8, 2019 to see a temperature as cold as -50 degrees, nearly two years ago. 

The low of -50 degrees Wednesday morning broke the record for the coldest this season in the lower 48. There's only been one place in the United States that's been colder than Antero Reservoir so far and that's in Birch Creek, Alaska with a temperature of -51 degrees measured on December 17.

Antero Reservoir sits about 140 miles southwest of Denver, Colorado. It is nestled within a mountain range and sits at about 9,000 feet above sea level.

The terrain around the reservoir is shaped like a bowl sitting at 9,000 feet in elevation, resulting in the perfect setup for extreme cold from time to time. 

The conditions for extreme cold were just absolutely perfect over the reservoir Tuesday night. It's a meteorological phenomenon known as radiative cooling and it happens when the skies are clear and winds are calm. 

When temperatures cool at night, the coldest layers of air sinks to the bottom and hovers near the ground. This is because cold air is more dense than warm air.

Given the terrain around the reservoir, the cold air drained down the mountains and pooled in the reservoir, resulting in a significant drop in temperature. 

This temperature has only been colder at the reservoir three other times since records began in 1961. The coldest was -54 degrees set in 1962.



The coldest temperature ever recorded in Colorado was -61 degrees which occurred in Maybell, CO on Februrary 1, 1985. Maybell is a small community located in northwestern Colorado. 

If you think that is frigid, how about -80 degrees! That's the coldest temperature ever recorded in the United States and it happened on January 23, 1971 at Prospect Creek, Alaska. 

Sub-zero temperatures have been recorded as far south as the Gulf Coast! 

Check out the map below to view the record low in your state of interest: