OVERNIGHT: Areas of dense freezing fog with lows around -13° for Idaho Falls, around -5°. Chance of light snow from the fog. Otherwise, mostly clear skies with wind chills at -15 to -30.
FRIDAY: Areas of freezing fog with highs into the upper teens. Sunny skies with winds around 10MPH.
SATURDAY: Highs into the upper 20's, winds around 5-10 MPH. Mostly sunny skies with some morning fog.
SUNDAY: Highs into the mid to upper 20's with sunny skies.