San SebastianPhoto: Ander.gd · CC BY-SA 4.0Spain · Europe
Best time to visit San Sebastian
San Sebastian is known for La Concha bay, pintxos bars and surfing. The climate is mild and Atlantic-damp, with pleasantly warm rather than hot summers. July to September is best, when the sea becomes swimmable.
Climate decision
Best travel months for San Sebastian
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Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Latest 5-year values 2021–2025
Average of the five most recent complete years compared with the 1991–2025 climate average.
June · Wet days
15 days/month
1991–2025: 11.3 days/month
+3.7 days/month · higher
October · Mean daily maximum
20.6 °C
1991–2025: 18.9 °C
+1.7 °C · higher
September · Monthly precipitation
119.7 mm/month
1991–2025: 83.7 mm/month
+36 mm/month · higher
August · Sea temperature
23 °C
1991–2025: 22.3 °C
+0.7 °C · higher
July: 5/155 days at or above 30 °C; highest single value 35.8 °C.
Five-year historical sample, not a weather forecast or long-term climate trend. Individual hot days can be far above the monthly mean.
Annual profile · Coast and sea
San Sebastian: the swimming season follows two curves
Average daily highs vary by 12.7 °C through the year, while the sea varies by 10 °C. Air and water temperature should therefore be considered separately.
The practical difference
The month with the highest daytime temperature and the month with the warmest sea need not define the same travel window. Rain and sunshine help resolve the trade-off.
Warmest sea
August · 22.3 °C
Highest average daily high
August · 23.8 °C
Fewest rainy days
July · 9.6
Most sunshine
June · 7.4 h
Month by month
Overall suitability per month. Tap a month for details.
All climate figures compared
The table is the complete accessible data view; the charts below highlight selected patterns.
| Month | Avg high °C | Avg low °C | Rainy days (est.) | Rain mm | Sun h/day (est.) | Humidity % | Wind m/s | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|---|
| January | 11 | 7 | 14 | 113 | 1.9 | 82 | 3.7 | 13 | 26 |
| February | 11 | 7 | 12 | 87 | 2.9 | 81 | 3.5 | 12 | 31 |
| March | 13 | 9 | 12 | 81 | 4.5 | 80 | 3.2 | 13 | 37 |
| April | 15 | 10 | 14 | 87 | 5.8 | 80 | 3.0 | 14 | 39 |
| May | 18 | 13 | 13 | 77 | 6.9 | 80 | 2.6 | 16 | 51 |
| June | 21 | 16 | 11 | 71 | 7.4 | 81 | 2.5 | 19 | 69 |
| July | 23 | 18 | 10 | 49 | 7.4 | 79 | 2.5 | 21 | 80 |
| August | 24 | 19 | 10 | 55 | 6.6 | 77 | 2.5 | 22 | 83 |
| September | 22 | 17 | 12 | 84 | 5.3 | 76 | 2.7 | 21 | 72 |
| October | 19 | 14 | 13 | 102 | 3.4 | 78 | 3.0 | 18 | 56 |
| November | 14 | 11 | 16 | 149 | 2.1 | 81 | 3.6 | 16 | 33 |
| December | 12 | 8 | 14 | 118 | 1.6 | 82 | 3.7 | 14 | 28 |
Climate through the year
Compare temperature, rainy days, sunshine and, for coastal destinations, sea temperature month by month.
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Where to stay in San Sebastian
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The number is the overall climate score, not a similarity score.
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Frequently asked questions
When is the best time to visit San Sebastian?
The strongest climate months are June, July, August, September. Values are historical averages, not a forecast.
Which month has the highest average daily maximum temperature in San Sebastian?
The average daily maximum temperature in San Sebastian is highest in August at around 24 °C.
When is the sea warmest at San Sebastian?
In August, at around 22 °C.