Pack or skip
Sunscreen for Busan in December
Verdict
Pack it
Sun still finds you at 50°F — UV doesn't care about temperature.
Why
Busan in December averages highs of 50°F, lows of 37°F, 5 rainy days.
That climate means sunscreen earns its space in the bag. Sun still finds you at 50°F — UV doesn't care about temperature.