Guethary - surf spot statistics

Best Surf Season (October - March)

The North Atlantic swings into full production mode during these six months, delivering a steady diet of powerful, long-period swell to the NW-facing shores of Guethary. Average wave heights hover between 1.3m and 1.8m, with periods consistently above 11s and often reaching 13s, putting the spot firmly into the pumping and firing categories. The climatalogical dip in the Azores High allows low-pressure systems to barrel across the basin, sending trains of W, WNW, NW and NNW swell straight into the Bay of Biscay. Offshore wind windows – driven by continental high pressure or the eastern flank of passing lows – occur 41-50% of the time, perfect for grooming those long, clean lines. December stands out as the statistical peak, but every month from October through March offers ample opportunity for classic Guethary barrels.

Fair Surf Season (April & September)

April and September represent the shoulder months, where the ocean still holds respectable swell but the consistency and power begin to wane. Average swell heights drop to 1.1-1.2m, periods shorten to 10.6-11.0s, and ideal wind frequency falls to around 29%. Swell directions remain dominated by WNW and NW – the bread and butter for this spot – but the mix is peppered with more small, weak pulses. Spring and autumn transition patterns often bring fickle conditions: some days deliver punchy, rideable waves, others are plagued by onshore breezes from the W or NW. For the patient surfer, these months can still yield solid sessions, especially when a late-season storm sneaks through and a high-pressure ridge parks itself over the continent, producing offshore flow.

Low Surf Season (May - August)

Summer at Guethary is a classic tale of diminished energy. From May through August, average swell heights bottom out at 0.9-1.0m and periods slump to 9.0-10.1s, often producing small, fun-sized or groveling conditions. The dominant swell still arrives from the NW and WNW, but the fetch is generally weak – either from distant tropical systems or lightweight Atlantic lows. More critically, the percentage of ideal offshore wind plummets to 15-23%, as the prevailing regime shifts to spring/summer westerlies and sea breezes that ruin the wave face. While the occasional long-period groundswell can sneak in from a rogue storm, the day-to-day reality is small, wind-affected surf. This is the season to save your energy, explore other spots, or wait for the autumn equinox to reignite the North Atlantic machine.

September: Autumn Awakening, Mixed Bag

September is the turning point at Guethary. The average swell height climbs back to 1.1m and period increases to 10.6s, signaling the return of meaningful energy. Swell direction remains NW (53.8%) and WNW (33.3%), but now there is a wider spread of heights: the 1-1.5m and 1.5-2m categories start to fill out, with 4.1% of waves in the 1.5-2m range from NW alone. The period shift to average to powerful means better shape and more push. Wind conditions improve notably: ideal offshore reaches 29% of the time. While onshore westerlies (W 12.0%, WNW 11.4%, NW 10.6%) still dominate, the increased frequency of E to SE winds (collectively ~15%) brings cleaner mornings and evenings. September’s transitional nature means you can get classic early‐autumn sessions: a building west swell from a distant hurricane combined with a continental high creating light offshore flow. Consistency is not yet peak, but the quality of the good days is already exceptional. Keep an eye on tropical activity in the Atlantic – those can send perfect long-period swell for a day or two.