San Sebastián Temperature by Month
The average annual maximum temperature in San Sebastián, Basque Country, Spain is 17°C (63°F), with daytime highs ranging from 12°C (54°F) in January to 24°C (75°F) in August. This page covers monthly averages, day-night differences, and how San Sebastián compares to cities worldwide.
San Sebastián Monthly Temperatures
The climate in San Sebastián is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 18°C (64°F) in August to 7°C (45°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in San Sebastián by month:
Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. August, the warmest month, sees 198 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in July
Historical San Sebastián Temperatures: 1976-2026
Browse day-by-day temperature records for San Sebastián spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: San Sebastián vs Spain
The map below shows the annual temperature across Spain. You can also select individual months if you want to compare a specific time of year.
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San Sebastián vs World: Temperature Compared
San Sebastián's average annual maximum temperature is 17°C (63°F). To put that in context, here's how it compares to a few well-known destinations:
Seville, Spain averages 23°C (73°F) a year — one of the warmer cities in Western Europe, with long hot summers.
Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.
Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
What Does the Temperature Feel Like in San Sebastián?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In San Sebastián, January is the coolest month, with average highs of 12°C (54°F) and humidity around 75% — considered high. In August, the warmest month, temperatures average 24°C (75°F) with 75% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.
Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.
For more on San Sebastián's weather — including monthly rainfall, sunshine hours, and humidity — visit our San Sebastián climate page.
