The National Weather Service has issued a Windchill Advisory for 5pm New Years Eve Day, December 31st to 8am New Years Day, January 1st for most of southeast Wyoming. With bitter cold wind chills as low as -25 below expected, frostbite could occur on exposed skin in as little as 30 minutes. Hypothermia is also a risk. If you are going out to celebrate New Years, make sure you are bundled up with hats, gloves and jacket. The forecast for Laramie on New Years eve says windchills of -20 to -30 below are to be expected.
Here is a link to the National Weather Service official Wind Chill Chart: https://www.weather.gov/safety/cold-wind-chill-chart