Pack or skip
Thermal underwear for Boston in December
Verdict
Pack it
Lows around 28°F — thermals are the difference between a walk and a march.
Why
Boston in December averages highs of 42°F, lows of 28°F, 12 rainy days.
That climate means thermal underwear earns its space in the bag. Lows around 28°F — thermals are the difference between a walk and a march.