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.

December: Peak Season Glory

December is the crown jewel of the surf calendar at Mejillones. Average swell height reaches 2.1m with a period of 12.6s – in the very powerful, long period zone. The swell directions are optimal: NNW (31%) and NW (19.2%) combined with a solid N component (8.1%) and WNW (8.1%). Critically, the ideal wind frequency peaks at 23% – the highest of any month. This means offshore S to SW winds blow nearly a quarter of the time, often accompanying high pressure after a strong frontal passage. The waves are consistently firing and heavy, with many days in the 1.5-2.5m range. The combination of massive swell and clean offshore wind creates the best surfing conditions of the year. If you only have one month to chase big waves at Mejillones, December is it.