The best time to visit San Sebastián is May, June, September and October, when average highs land in a comfortable band — June reaches 22.2 °C and September 23 °C — with plenty of sunshine and manageable rain days (June and September each see roughly 14 and 13 rain days). July and August are the peak season, warmest of all at 24.6 °C in August but crowded with school-holiday visitors and higher prices. Winter is the quiet low season, cool and grey with highs around 12.1 °C in January and short sunshine days.
Best months MayJuneSeptemberOctober
San Sebastián month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sun / day |
|---|---|---|---|---|
| January | 12.1 °C | 6.1 °C | 16 | 5.3 h |
| February | 14.1 °C | 7.1 °C | 14 | 6.7 h |
| March | 15.1 °C | 8 °C | 17 | 8.2 h |
| April | 16.9 °C | 9.5 °C | 15 | 9.2 h |
| May | 19.2 °C | 11.8 °C | 16 | 10.4 h |
| June | 22.2 °C | 15.4 °C | 14 | 10.3 h |
| July | 23.6 °C | 17.2 °C | 13 | 11 h |
| August | 24.6 °C | 17.5 °C | 12 | 10.8 h |
| September | 23 °C | 15.6 °C | 13 | 9.8 h |
| October | 20.6 °C | 13.4 °C | 13 | 7.5 h |
| November | 15.7 °C | 9.7 °C | 17 | 5.9 h |
| December | 13.8 °C | 8 °C | 15 | 5.2 h |
How the months are picked.A month qualifies when its average high sits in the comfortable 20–28 °C band (scored down towards 9 °C and 37 °C), rain days are few and sunshine hours are high — at least 78 % of the city's best-scoring month. July and August are then set aside as peak season (school-holiday crowds and prices) whenever at least three other months qualify; where summer is the only comfortable window they stay. Figures are ten-year averages (2016-01-01 to 2025-12-31) from ERA5 reanalysis data via Open-Meteo (CC BY 4.0) for the city centre coordinates.
When to go, and what to expect
Spring (Mar–May)
Green, fresh and uncrowded — great for walks along La Concha before summer arrives.
Summer (Jun–Aug)
Best beach weather but July–August is busy and pricey; June is the sweet spot.
Autumn (Sep–Nov)
September and October are ideal — warm sea, fewer people, film-festival buzz.
Winter (Dec–Feb)
For pintxos, museums and moody coastal views rather than the beach.
Notable events
- January (20th, Saint Sebastian's Day)
- Tamborrada (drum festival)
- September
- San Sebastián International Film Festival
- August
- Semana Grande / Aste Nagusia summer festival
- July
- Jazzaldia jazz festival
Frequently asked
Is August too hot in San Sebastián?
No — August highs average 24.6 °C, warm but not extreme. The bigger factor is crowds, as it's peak school-holiday season with the busiest beaches and highest prices.
What is the rainiest month?
Rain is spread through the year, with March and November the wettest at 17 rain days each. Even summer months like June still see 14 rain days, so pack a light layer.
Is winter worth visiting?
Winter is quiet and cool — January highs of 12.1 °C and just 5.3 hours of sunshine a day, plus 16 rain days. It's not beach weather, but it suits pintxos, museums and the January Tamborrada festival.
Know when to go? Now decide where to stay — our San Sebastián area guide →
Areas of San Sebastián
Best time to visit near here
Sources
- Open-Meteo historical weather API — monthly climate normals, 2016–2025 (CC BY 4.0)
- ERA5 reanalysis (ECMWF / Copernicus) — the underlying temperature, precipitation and sunshine data
- ReasonStay methodology — how the best months are computed and checked
An independent guide to San Sebastián — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.