Will I be hot?
Will I be hot in Harrison in December?
Verdict
No — No, comfortable.
Highs cap at 45°F — no heat-management gear needed.
Day vs. night
Day
45°F
Cold
Direct sun feels cool at best; shade is jacket weather.
Night
32°F
Cold
Cold enough that a hat and gloves become mandatory.
Why
Harrison in December averages highs of 45°F, lows of 32°F, 10 rainy days.
Temperature is comfortable across the day; pack for style and weather resistance, not heat management.