San Francisco weather in December 2026

December in San Francisco is cool and damp, with average highs of 13.7°C (56°F) and lows around 8°C (46°F). Rainfall averages 127.3 mm spread across roughly 10 rainy days, so you'll see plenty of grey mornings and sudden downpours, but the sun still manages about 6.7 hours daily. The city feels crisp and restless—locals bundle in layers, the bay water is cold enough to keep swimmers out, and the fog rolls in thick most afternoons before burning off briefly around midday.

The holiday season transforms San Francisco into something between a working city and a festival. Union Square fills with shoppers and Christmas decorations, ferry terminals get crowded with tourists heading to Alcatraz and Marin, and restaurants book up weeks ahead. At the same time, the weather keeps casual crowds thin—you'll find quieter mornings at Golden Gate Park and shorter lines at museums. Prices spike around Christmas week but stay reasonable earlier in the month. Locals retreat indoors, making dive bars and cosy cafés genuinely packed, while beaches and hiking trails stay surprisingly empty.

December 2026 aligns closely with the 10-year average for San Francisco. The city's marine climate is remarkably stable, so expect typical winter conditions—no extreme cold snaps, no unusual dry spells. Rain patterns have been consistent, and the ratio of grey to sunny days remains predictable. If anything, December feels milder than many East Coast winters, which is why it attracts visitors looking to escape harsher climates.

December suits photographers (moody light, holiday decorations), budget travelers (fewer peak-season crowds outside holidays), and anyone who loves cities in a quieter gear. Families often visit for school holidays starting mid-month. If you're planning 2026 travel to San Francisco in December, book accommodation and restaurants early for the 15th onwards, but don't hesitate to explore the first two weeks when the city breathes a little easier. Bring a waterproof jacket, expect rain any afternoon, and dress in layers—you'll shed them midday if the sun appears.