Pack or skip
Thermal underwear for Chicago in December
Verdict
Pack it
Lows around 22°F — thermals are the difference between a walk and a march.
Why
Chicago in December averages highs of 36°F, lows of 22°F, 11 rainy days.
That climate means thermal underwear earns its space in the bag. Lows around 22°F — thermals are the difference between a walk and a march.