Weather in Сан-Себастьян by month: what to expect

Сан-Себастьян enjoys a mild oceanic climate, with gentle seasonal shifts that make it a year-round destination. Winters here are cool but rarely harsh, while summers stay comfortably warm without extreme heat. The city’s proximity to the Bay of Biscay moderates temperatures, keeping Сан-Себастьян from swinging too far in either direction.

Rainfall is spread throughout the year, though Сан-Себастьян sees noticeably wetter periods in November and December, when storms from the Atlantic bring heavier showers. The driest stretch falls in July, offering the most reliable sunshine for beachgoers and outdoor explorers. Even in the wettest months, rain rarely spoils a full day—showers tend to come and go, leaving plenty of time to enjoy the city.

Daylight varies modestly across the year, with the shortest days in December and the longest in June. Even in winter, Сан-Себастьян rarely feels gloomy, thanks to its coastal setting and frequent breaks in the clouds.

Temperatures in Сан-Себастьян follow a steady rhythm, with the coolest months—January and February—averaging around +8.6 °C to +10.1 °C. Even at its coldest, the city rarely dips below +6 °C at night, making winter chilly but not bitter. By March, the air begins to warm, and by May, daytime highs reach a pleasant +18.1 °C, ideal for strolling along La Concha or exploring the Old Town.

Summer in Сан-Себастьян is warm but never stifling, with July and August bringing the highest temperatures, peaking around +22.4 °C to +23.3 °C. Nights remain mild, rarely dropping below +17 °C, so evenings are perfect for dining al fresco or taking a sunset walk along the promenade. The sea warms up too, reaching +23.3 °C in August, inviting swimmers and surfers alike.

Autumn arrives gradually, with September still feeling like summer at +18.7 °C, while November cools to +12 °C. The transition is smooth, with no sudden drops, so even in late autumn, Сан-Себастьян retains its charm. By December, temperatures settle back into the +10.5 °C range, rounding out the year with the same mild conditions that began it.

Rain is a constant presence in Сан-Себастьян, but its intensity shifts with the seasons. The wettest months—November and December—see the most rainfall, with November alone bringing 256.4 mm. These months can feel damp, with frequent showers, though they rarely last all day. Even in the rainiest periods, there are usually dry spells to explore the city’s cafés, museums, or coastal paths.

From April to August, rainfall eases, with July being the driest month at just 82 mm. This stretch offers the most reliable weather, though even in summer, a light shower isn’t uncommon. The city’s lush greenery thrives on this steady moisture, so don’t be surprised to see vibrant parks and gardens even in the drier months.

Spring and early autumn bring moderate rainfall, with May and September seeing around 113.5 mm and 136.9 mm, respectively. These months strike a balance—enough rain to keep the landscape fresh, but not so much that it disrupts plans. If you’re visiting Сан-Себастьян in October, pack a light rain jacket, as showers become more frequent as winter approaches.

For a trip to Сан-Себастьян in winter, layering is key. Days in January and February hover around +8.6 °C to +10.1 °C, so a warm sweater, a waterproof jacket, and comfortable walking shoes will keep you comfortable. Evenings can feel cooler, so a scarf and gloves might come in handy, especially if you’re out near the water.

Spring and autumn call for versatile clothing. In April or October, temperatures range from +12.5 °C to +16.2 °C, so light layers—like a long-sleeve shirt, a light jacket, and a scarf—work well. A compact umbrella or a waterproof shell is useful for the occasional shower, particularly in November or March. Comfortable shoes are a must, as Сан-Себастьян’s hilly streets and coastal paths are best explored on foot.

Summer in Сан-Себастьян is all about staying cool and sun-smart. In July and August, temperatures reach +22.4 °C to +23.3 °C, so pack breathable fabrics, a sun hat, and sunglasses. A light sweater is still useful for breezy evenings, and a swimsuit is essential if you plan to take a dip in the sea, which warms to +23.3 °C in August. Don’t forget sunscreen—even on cloudy days, the sun can be strong.