Mejillones - surf spot statistics

Best Surf Season (October - March)

The North Atlantic roars to life during these months, delivering a consistent barrage of powerful, long-period swell to Mejillones' north-northwest facing beach. With average wave heights hovering between 1.7m and 2.2m and periods often exceeding 11 seconds, the potential for pumping and firing conditions is at its peak. The ideal offshore wind (S to SW) blows with moderate frequency, especially in December (23% ideal) and January (19%), creating clean, glassy faces when the synoptic setup aligns. This is undoubtedly the prime window for scoring the best waves of the year.

Fair Surf Season (April & September)

Transitional months like April and September offer a mix of fading winter swell and building autumn energy. Average heights drop to around 1.4-1.9m and periods shorten to 10-11 seconds, but quality windows still present themselves when a late-season low or early-season hurricane sends a clean NW swell. Ideal wind frequency drops to 5%, making these months more of a gamble. However, when conditions align, you can still find fun-sized waves with less crowd pressure.

Low Surf Season (May - August)

Summer brings a drastic reduction in surf potential. The North Atlantic storm track shifts north, producing negligible long-period groundswell. Average heights remain around 1.4-1.6m, but periods slump to 7.7-9.5s, resulting in predominantly choppy, messy wave conditions. Dominant winds shift to strong northerly quadrants (NNE, NE) that blow directly onshore, ruining any semblance of shape. Ideal offshore winds are nearly nonexistent (0-2% of the time). These months are best left for other activities unless a rare tropical system aligns perfectly – a true low surf season.

January: The Heart of Winter Swell

January is the apex of the North Atlantic storm machine, with an average swell height of 2.2m and a commanding period of 12.9s – squarely in the powerful, long period category. The swell rose is dominated by NNW (34.8%) and NW (19.5%) directions, both of which wrap perfectly into Mejillones' NW-facing beach. A further 7.3% comes from due N, also favorable. Wave heights are robust, with over 60% of the swell in the 1.5-2.5m range, offering pumping to firing conditions. The wind, however, is a mixed bag. While the dominant NNE (16.7%) and NE (22.7%) winds are onshore and can chop up the surface, S to SW offshore breezes blow 19% of the time – often during post-frontal high pressure. When that offshore wind cleans up a solid NW groundswell, the result is truly world-class.