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.

January: The Depth of Winter Power

January is the heart of the winter season at Arenillas, with an average swell height of 2.0m and a long period of 12.9s. Swell direction is overwhelmingly from the NW (36.7%) and WNW (18.6%), but these are not optimal for our NNE-facing beach – they often bring onshore winds from the same direction. The good news: 42% of the time the wind blows from the S, SSW, and SW quadrants, providing clean offshore conditions. When a proper northerly swell (N, NNE, NNW combined 16.7%) coincides with these offshore winds, the surf becomes truly world-class. The long period ensures powerful, walled-up waves that peel nicely along the sandbars. Keep an eye on the NAO index – a negative phase can push storm tracks southward, increasing the likelihood of those ideal northerly swells.