From the U.S. National Weather Service Missoula Montana: A combination of winds and very cold ambient temperatures will cause wind chills to exceed 30 to 40 degrees below zero for western Montana and north central Idaho Tuesday morning.
Protect any exposed skin to keep frostbite threat at bay, and take extra care for any susceptible livestock or pets that could be affected by these bitterly cold temperatures. Please dress accordingly if you have to be outside Tuesday, as wind chill values are going to be brutal.