Pack or skip
Sunscreen for Lucerne in September
Verdict
Pack it
Sun still finds you at 65°F — UV doesn't care about temperature.
Why
Lucerne in September averages highs of 65°F, lows of 49°F, 10 rainy days.
That climate means sunscreen earns its space in the bag. Sun still finds you at 65°F — UV doesn't care about temperature.