Verdict: Fair month
San Sebastián Weather in December
December is mild-to-cool in San Sebastián, topping out near 14°C (57°F) — comfortable with a layer on. It's also the wet side of the calendar: rain falls on about 17 days, so build flexibility into plans. December is workable in San Sebastián if your dates are fixed — just plan around the conditions.
Average high
14°C / 57°F
Average low
8°C / 46°F
Rain days
~17
Precipitation
240 mm
What to pack for San Sebastián in December
- Layers — t-shirts under a light jacket or sweater
- Rain gear is non-negotiable — expect rain on roughly 17 days
- Comfortable walking shoes — every guide on this site assumes you'll use them
December against the rest of the year
Warmest in San Sebastián: Aug (25°C / 77°F) · Coolest: Jan (12°C / 54°F) · Wettest: Dec (~17 rain days)
12°
6°
Jan
15°
8°
Feb
16°
8°
Mar
17°
10°
Apr
20°
12°
May
22°
15°
Jun
24°
17°
Jul
25°
18°
Aug
23°
16°
Sep
21°
14°
Oct
16°
10°
Nov
14°
8°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)