Zarautz - surf spot statistics

Best Surf Season (October - March)

The North Atlantic flexes its muscles during this window, delivering a consistent barrage of powerful, long-period swells from the NW quadrant. Average wave heights hover around 1.8-2.1m, with periods frequently exceeding 12s, meaning the sets are packing serious punch. The strengthening Azores High and deepening Icelandic Lows set up a classic pressure gradient that funnels storm energy right into the Bay of Biscay. Crucially, offshore winds from the S to SSW dominate 40-45% of the time, grooming the lines for peaky, hollow waves. This is the heart of the season – expect firing conditions for experienced surfers, especially when the window aligns with a negative NAO phase.

Fair Surf Season (April, May, September)

Transition months bring a mix of leftover winter energy and early summer lulls. Average heights drop to 1.2-1.5m and periods shorten to 9-11s, so the power diminishes. Swell direction still favors NW-WNW, but the percentage of ideal offshore winds falls to 29-33%. You’ll find fun-sized waves rather than pumping sets, with cleaner conditions often limited to the mornings before sea breezes kick in. April and September can still surprise with a solid NW groundswell, but consistency wanes. May is weaker, though a south wind setup can save a flat day.

Low Surf Season (June - August)

Summer settles in with a dramatic drop in both swell size and quality. Average wave heights hover around just 1.0m, periods dip to 8.8-9.2s, and the ideal offshore wind window shrinks to a paltry 18-22%. The dominant swell direction remains NW (over 60% of total), but it’s mostly short-period, windswell-driven lines that struggle to break cleanly on the sandbar. Onshore NW winds plague the afternoon, turning the surf into bumpy, weak 1ft foam. Occasional thunderstorms to the south can spit out a brief SSW offshore, but don’t expect anything over waist-high. This is groveling time – best for beginners or longboards in the small summer corners.

April: Spring Transition

April sees average wave heights drop to 1.5m and period decrease to 10.8s – we’re now in the fun, good category. Swell direction is still dominated by NW (39.3%) and NNW (15.5%), but the percentage of larger waves (>1.5m) declines. The ideal wind window narrows to 33%, with offshore S/SSW winds at 7.3% and 5.2% respectively. Onshore NW and WNW winds combine for over 21% of the time, often bringing bumpy conditions. The good news: when a south wind aligns with a NW swell, the waves can be peaky and well-shaped. April offers a mix of leftover winter groundswell and new spring systems, but patience is needed to catch the clean windows.