Will I be hot?
Will I be hot in Seoul in January?
Verdict
No — No, comfortable.
Highs cap at 36°F — no heat-management gear needed.
Day vs. night
Day
36°F
Cold
Direct sun feels cool at best; shade is jacket weather.
Night
21°F
Freezing
Deep freeze after sunset — every exposed step counts.
Why
Seoul in January averages highs of 36°F, lows of 21°F, 6 rainy days.
Temperature is comfortable across the day; pack for style and weather resistance, not heat management.