Extreme Cold/Wind Chill in Southern Foothills, South Dakota

An arctic air mass settled over the region for several days, producing extreme and dangerous wind chills across western and south-central South Dakota. Temperatures remained below zero for 3 days, as low as 20 below to 40 below zero across much of the area on the mornings of the 13th and 14th. Gusty north to northwest winds at times helped to produce wind chills in the 30 below to 70 below range from the morning of the 13th to the morning of the 15th.