Conditions at Cap Sim in December
December: Peak Winter Groundswell
December is Cap Sim at its winter best. The average swell height is 7.2ft (2.2m) and the period is a powerful 12.8 seconds. While the dominant directions are still NNW at 31 percent and NW at 23 percent, December shows the strongest monthly WNW, W, WSW and SW presence of the entire winter: WNW at 11 percent, W at 2.5 percent, WSW at 1.4 percent and SW at 0.7 percent. That extra westerly component is exactly what the west-southwest-facing spot needs to turn on. Ideal wind is up to 51 percent, driven by NE at 25 percent, ENE at 16 percent and NNE at 12 percent offshore flow. When storm systems track lower into the North Atlantic, Cap Sim can see properly heavy, pumping surf.
Water temperature drops to 17.2°C with average air temps of 16.8°C and rain at 1.38 mm/day. This is the heart of the surfing season - bring warm boots and hold on.
Average Spot conditions at Cap Sim in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Cap Sim during December. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at Cap Sim for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Cap Sim for December. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at Cap Sim.