Will I be hot?
Will I be hot in Paris in December?
Verdict
No — No, comfortable.
Highs cap at 48°F — no heat-management gear needed.
Day vs. night
Day
48°F
Cool
Sweater weather with the option to add a light shell.
Night
39°F
Cold
Cold enough that a hat and gloves become mandatory.
Why
Paris in December averages highs of 48°F, lows of 39°F, 11 rainy days.
Temperature is comfortable across the day; pack for style and weather resistance, not heat management.