Arenillas - surf spot statistics

Best Surf Season (October - March)

The North Atlantic winter pattern delivers consistent, powerful swell from the NW quadrant. However, at Arenillas, the ideal window aligns when the swell swings more northerly (N to NNE) and is accompanied by offshore S-SSW winds. These months see the highest average wave heights (1.5m-2.0m) and longest periods (11-14s), providing a solid platform for good surf. The percentage of ideal wind conditions peaks at 38-42%, meaning that a significant portion of the days offer clean, offshore conditions. The combination of long-period groundswell and favorable wind makes this the prime time for Arenillas.

Fair Surf Season (April & September)

Shoulder months see a transition. April still has moderate swell (1.4m avg, 10.9s period) but ideal wind drops to 31%. September sees similar stats (1.2m, 10.4s, 32%). The swell direction remains predominantly from the NW, but the wind patterns become more variable, with fewer consistent offshore windows. You can still score good waves, but you'll need to be selective.

Low Surf Season (May - August)

The summer months bring smaller, weaker swell (0.9-1.1m, periods 8-10s). The dominant NW swell is still present but much less organized, often mixed with short-period windswell. Ideal wind percentages drop to 22-30%, meaning onshore winds (from N-NW) frequently ruin the waves. The surf is generally small and mushy, with only rare opportunities for decent waves when a southerly breeze cleans up the leftover swell. This is a time for groveling and longboard sessions at best.

September: Autumn Stirrings

September marks the beginning of the autumn transition. Average swell height rises to 1.2m and period to 10.4s. The NW remains the primary swell direction (53.8%), but there is a noticeable increase in more northerly swells – NNE jumps to 5.7% and NNW to 21.9%. This shift, combined with a rise in ideal wind percentage to 32%, signals that the surf season is slowly returning. The first strong low-pressure systems begin to develop in the North Atlantic, sending longer-period swell our way. Still, the wind can be fickle – morning offshore breezes often give way to afternoon onshores. Watch for days when a high-pressure ridge extends into the Bay of Biscay, creating a clean S-SSW flow all day.