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Conditions at Oceanside in December
December: Pristine Winter Groundswell
December delivers the best combination of wave height, period, and wind quality all year at Oceanside. Average swell height is 1.0m (3.3ft), and the direction mix is heavily biased toward the optimal W and WSW windows: W at 54.6%, WSW at 28.9%, and SW at 10.6%. The W direction is especially consistent, with 30.1% of waves in the 2-3ft (0.5-1m) range, 18.5% in the 3-5ft (1-1.5m) range, 4.5% in the 5-6.5ft (1.5-2m) range, and 1.1% in the 6.5-8ft (2-2.5m) range. With a 12.6s period, this is classic long-period North Pacific groundswell.
The wind story is excellent: ideal offshore conditions occur 51% of the time, the best of any month along with January. NNE and NE winds are common at 12.8% and 12.3%, while the onshore W flow is suppressed to just 9.7%. Water temp is 15.0°C (59.0°F), air temps hover around 14.8°C (58.6°F), and rainfall averages 1.71mm/day. This is the heart of the winter season - when the swell and wind align, Oceanside is as good as it gets.
Average Spot conditions at Oceanside in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Oceanside 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 Oceanside for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Oceanside 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 Oceanside.