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.

April: Spring Swell, Fickle Winds

April is the true shoulder month. Average swell height dials back to 1.2m and period drops to 11.0s, producing waves that are still good and solid but less consistent in power. The dominant swell directions remain WNW (42.1%) and NW (40.4%), with a significant increase in smaller swell: over 50% of the waves from these directions fall in the 0.5-1m and 1-1.5m ranges. That’s excellent for grovel boards and logging, but the top-end juice is harder to come by – only 6.7% of waves exceed 1.5m. The wind outlook is more challenging: ideal offshore conditions occur just 29% of the time. Onshore flow from W (12.8%) and WNW (12.4%) is common, often the result of persistent low pressure over the Bay of Biscay. The saving grace is the increased frequency of SE to SSE winds (collectively ~10%), which can blow side-offshore clean for a NW-facing beach. To get the most out of April, you need to pick your windows – typically a day or two after a strong frontal passage, when the swell has settled and a continental high moves in.