Pack or skip
Flip-flops for San Diego in December
Verdict
Optional
Warm enough to wear in the evening or on the beach; not on a city walking day.
Why
San Diego in December averages highs of 66°F, lows of 50°F, 5 rainy days.
That climate makes flip-flops a judgment call. Warm enough to wear in the evening or on the beach; not on a city walking day.