Pack or skip
Sunscreen for Osaka in January
Verdict
Pack it
Sun still finds you at 48°F — UV doesn't care about temperature.
Why
Osaka in January averages highs of 48°F, lows of 35°F, 6 rainy days.
That climate means sunscreen earns its space in the bag. Sun still finds you at 48°F — UV doesn't care about temperature.