Andran - surf spot statistics

Best Surf Season (October - March)

The North Atlantic winter machine fires up in October, and Andran sees a steady climb in average swell heights through March. Dominant NW groundswells – born from powerful extratropical storms – march into the bay with long periods averaging 11-13 seconds, producing consistent head-high to well-overhead sets. The key is wind: during winter, the percentage of offshore southerly winds (S-SW) peaks at 45-46% in December and January, creating clean, glassy faces on the NNE-facing beach. When a low-pressure system stalls over the Bay of Biscay and a high builds to the southwest, the resulting pressure gradient delivers light offshore breezes that groom the swell into long, peeling lines. This is the prime window for Andran, offering rippable waves day after day.

Fair Surf Season (April & September)

As spring and autumn transition months, April and September sit in a middle ground. Swell heights drop to around 1.2-1.4m on average, and periods shorten slightly to the 10-11 second range. The NW swell still dominates, but the fetch is less aggressive. More critically, offshore wind frequency falls to 20-26%. You’ll often see mornings with light cross-shore breezes that clean up the swell before the sea breeze kicks in from the east or north. These months deliver fun, waist-to-shoulder-high waves when the conditions align. It’s a gamble, but the rewards can be solo sessions with clean walls.

Low Surf Season (May - August)

Summer is the quietest period for Andran. Average swell heights bottom out at 0.9-1.1m, with periods averaging just 8-9 seconds – a mix of short-period windswell and weaker background swell. The dominating force becomes the thermal low over Iberia, which pumps in easterly and northeasterly winds that blow directly onshore or cross-shore, ruining the wave shape. Offshore wind probability plummets to 13-15%. The few rideable days occur when a rare southerly breeze or early morning glass-off coincides with a small NW pulse. Most days, the surf is ankle-to-knee high and choppy – best suited for a longboard or a paddleboard.

March: Transitioning Energy

March sees a slight pullback in average swell height to 1.7m, with periods averaging 12.0s – still solid. The NW quadrant continues to dominate (43% due NW), but the frequency of larger 2-2.5m waves decreases. The wind picture becomes more mixed: offshore wind probability drops to 33%. This is due to the strengthening of the thermal gradient, which begins to favour easterly winds (ENE and E combine for 24% of the time). Those winds blow side-offshore to cross-onshore, degrading the wave face. The best windows occur when a late-season cold front swings through and the wind backs to the SW. March still offers plenty of chest-to-head-high surf, but you’ll need to work around the increasing easterly influence.