Conditions at Penarronda in December
December: Long-Period Winter Heavyweights
December closes the year at full strength. Average swell height is 5-6ft (1.6m), the average period stretches to 12.3s, and ideal wind days hold at 47 percent. NW swell dominates at 33 percent, NNW at 21 percent, WNW at 14 percent, and NNE adds 7 percent. The long-period nature of the December swells makes Penarronda stand up faster, pitch harder and produce much more powerful and well-ordered waves. This is heavy, powerful groundswell season in the Bay of Biscay.
Offshore wind is abundant: S, SSW and SW combine for about 47 percent of observations, with SSW alone at 21 percent. Onshore winds from the north and northwest are less frequent, so when the swell arrives, it is often clean. Water temperature is 14.1°C, air averages 9.2°C, and precipitation is 3.60 mm/day. December offers some of the most consistent, heaviest and most rewarding surf of the year for the surfer willing to embrace the cold and the rain.
Average Spot conditions at Penarronda in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Penarronda 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 Penarronda for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Penarronda 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 Penarronda.