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.

September: Autumn Revival Begins

September marks a turnaround: average swell height climbs to 1.3m, period to 10.4s – now in the fair, rideable range. NW swell remains king at 53.5%, with WNW (21.0%) adding more variety. The percentage of waves over 1m increases, offering more grunt. Ideal wind conditions improve to 32%, with offshore S (7.0%) and SSW (4.9%) becoming more common. Onshore winds from NW (8.3%) and WNW (10.1%) still appear but weaken. The early autumn equinox brings stronger storm tracks, and September often delivers the first solid groundswell of the season. Days with a clean south wind and a building NW swell can produce firing beach breaks.