San Sebastián weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Poor
Best time to visit: May – October
What is the weather like in San Sebastián in December?
In December, San Sebastián is cool: daytime highs average 12 °C, and nights cool down to about 7 °C. The sea averages 14.0 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. It rains often – on about 15 days, adding up to 136 mm. All in all, December is not an ideal month for a holiday in San Sebastián.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 34 | 26 | 20 |
| Day | 14° | 12° | 11° |
| Night | 10° | 7° | 7° |
| Sea | 16° | 14° | 13° |
| Sun | 3 h | 3 h | 3 h |
| Rain days | 17 | 15 | 16 |
More details for December
- Daylight
- 9 h 0 min08:33 – 17:33
- UV index
- 1 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 21 km/haverage daily peak
- Cloud cover
- 70 %on average
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+1Europe/Madrid
How the score comes together
- Temperatureweight 50 %39 %
- Sunshineweight 20 %0 %
- Few rainy daysweight 30 %21 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in December
- A jumper for the evenings
- Rain jacket or umbrella
San Sebastián in December: quick answers
Is San Sebastián hot in December?
No. In December, San Sebastián is cool: daytime highs average 12 °C and nights drop to about 7 °C.
Can you swim in San Sebastián in December?
Only if you don't mind cold water: in December the sea averages just 14.0 °C. Comfortable swimming is possible from July to September.
Does it rain much in San Sebastián in December?
It rains often – on about 15 days, adding up to 136 mm.
San Sebastián month by month
The whole year in San SebastiánAll destinations: SpainWhere to go in DecemberSea temperature in December
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)