The highest day temperature in January 2026 was 59°F. The lowest night temperature was 28°F. The average values for day and night temperatures during January were 49.8°F и 42.1°F respectivly.

The average sea surface temperature in January 2026 for San Sebastian was 56.9°F. The maximum and minimum values were 55.6°F and 59.0°F respectively.

Most of the days in January are gloomy but you can also expect sunny days.

Precipitation total in January for San Sebastian is 4.6 in. It makes january one of the most rainy months of the year.

The average wind speed in January is 8.6 mph. It makes January one of the most windy months of the year for San Sebastian.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for San Sebastian in January is 4.5 hours.