Pack or skip
Packable down jacket for San Diego in December
Verdict
Pack it
Lows around 50°F — the packable puffer covers 90% of layering needs.
Why
San Diego in December averages highs of 66°F, lows of 50°F, 5 rainy days.
That climate means a packable down jacket earns its space in the bag. Lows around 50°F — the packable puffer covers 90% of layering needs.