Conditions at Ohama in December
December: Big Winter Swell Meets Strong Offshore Winds
December signals full winter mode. Average height rises to 6ft (1.8m), with W-direction swell holding a 30% share and ENE adding 11% of east energy. Periods are short at 7.2s, so the ocean is powerful but lumpy, with plenty of windswell in the mix. Offshore W/WNW flow is the most dominant of the year, with W alone blowing 37% of the time and combined offshore directions approaching 52%, giving Ohama many glassy, offshore mornings. The problem is swell direction: only the E/ESE/SE/SSE window totals about 15%, so the biggest days often arrive on cross and offshore W/NE swell or with lots of residual chop. Still, when a low-pressure system passes south and pumps ESE/SE swell into the bight under NW winds, December can deliver firing, punchy surf. Water temperature is 18.9°C, air averages 13.3°C, and rain is lower at 2.5mm/day.
Average Spot conditions at Ohama in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Ohama 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 Ohama for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Ohama 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 Ohama.