Conditions at Reef in December
December: Winter's Grand Entrance
December closes the year as one of the most reliable big-wave months on the Portuguese coast. Average swell height is 8.2ft (2.5m), average period is 12.7 seconds, and the directional spectrum is a beautiful mix of NW at 21.2%, WNW at 15.2%, NNW at 11.3%, and W at 6.1%, all of which are in the optimal window for this west-facing reef. The long-period groundswell is powerful, consistent, and often accompanied by solid overhead to double-overhead waves.
December also features the highest frequency of offshore east to southeast winds of the entire year - around 28% of readings - with ideal conditions at 25%. The wind distribution is far more balanced than in summer: ENE, E, and ESE all see meaningful percentages, mixed with the usual NNW/N regimes from post-frontal highs. Water temperature falls to 14.9°C, air averages 12.3°C, and precipitation is healthy at 2.69mm/day. If you are looking for European winter perfection, clear a week in December and wait for the right window; the reef will be firing.
Average Spot conditions at Reef in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Reef 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 Reef for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Reef 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 Reef.