Zurriola - surf spot statistics

Best Surf Season (October - March)

The heart of the North Atlantic storm track delivers consistent, powerful swell to this northwest-facing beach. From October through March, average swell heights hover between 1.6m and 2.1m with long periods (11-13s), providing punchy, rippable waves on the best days. The dominant swell directions are NW, WNW, and NNW—all squarely in the window for Zurriola. Wind percentages are at their annual peak, with offshore flow from the S and SSW quadrant blowing 40-46% of the time. Frontal passages and deep low-pressure systems spinning out of the Labrador Sea generate solid groundswell trains that wrap into the bay. When the timing aligns with light offshore winds and clearing skies, you get firing, glassy conditions.

Fair Surf Season (April & September)

These shoulder months see a noticeable drop in average swell energy—April sits at 1.5m / 10.8s, September at 1.3m / 10.4s—but still offer decent, fun-sized waves. The North Atlantic begins to transition: spring low-pressure systems are less frequent, and autumn highs start to build. Ideal wind frequency falls to around 32%, meaning you'll need to pick your windows carefully. NW and WNW swells still dominate, but wave heights are smaller and more variable. Surfable conditions occur on days when a late-season storm or early-autumn cold front tracks favorably, bringing a clean, long-period swell that coincides with a southerly breeze. Those are the moments when the lineup comes alive without the heavy crowds.

Low Surf Season (May - August)

Summer settles in and Zurriola's swell engine goes into low gear. Average heights drop to 1.0-1.2m with periods around 8-9s, yielding mostly weak, short-period swell that struggles to push above chest-high. The wind picture also worsens: ideal offshore wind percentages plummet to 18-29%. NW and WNW swells still occur but are dominated by short-period windswell rather than groundswell. Frequent onshore north-northwesterly wind (bad, riffles the surface) and strong sea breezes combine to create choppy, messy conditions more often than not. Small surf but still rideable on days when a weak low passes or a thermal low pumps in a light southerly breeze. Expect groveling conditions on shortboards or longboards – definitely not the time for epic pits. Local summer cyclones (medicanes) are rare but can throw a wildcard swell into the mix.

September: Autumn Revival Kicks Off

September marks the turning point – average swell climbs to 1.3m with a period of 10.4s, and ideal wind jumps to 32%. The NW (53.5%) and WNW (21%) swell directions are back, and there's a noticeable increase in larger sets: 4.2% of WNW swell is 1.5-2m, and 2.3% in 2-2.5m. The wind rose shows that onshore N-NW wind is still around (N 8.2%, NW 8.6%, NNW 7.8%), but the frequency of offshore S wind increases to 7.7% (S) and 4.6% (SSW). This is the month when the first strong extratropical storms of the season form in the North Atlantic. These storms, often associated with a positive NAO phase, generate long-period groundswell that barrels into the Bay of Biscay. The days are still long and often warm, so a combo of sunshine, light offshore wind, and chest-high plus swell makes for excellent sessions. September is the hidden gem of the shoulder season – fewer crowds than summer, but the surf quality is on the upswing.