Conditions at Ondarreta in January
January: Midwinter Power and Clean South Winds
January is one of the heaviest months of the year at Ondarreta. Average swells run around 2.1m (7ft) and the average period hits 12.7s, putting almost every swell in the powerful, long-period class. The dominant directions are WNW and NW, with 28.3% of all swell coming from the NW and another 25.8% from the WNW; NNW adds 7.9%, meaning the North Atlantic is consistently feeding the Bay of Biscay. When that W/NW energy mixes with N/NNW swell and refracts around the headland, the sets take shape nicely.
Wind makes January a standout. The S/SSW/SW offshore flow is present a large share of the time-S alone makes up 20.2% of the wind distribution and SSW another 10.3%-and the overall ideal-wind percentage sits at 46%. That means plenty of clean, blowing-offshore days even when winter storms and fronts rumble through. Expect cold air for Spain: air temps average just 9.1°C, with lows possible below freezing, while water temps sit at 13.2°C. Suit up in solid winter rubber, booties and gloves, and pick your windows when the southerly wind cleans up the long-period swell.
Average Spot conditions at Ondarreta in January
Swell history for January
Wind history for January
Swell quality
Analyze the groundswell consistency at Ondarreta during January. 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 Ondarreta for your next trip in January.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Ondarreta for January. 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 Ondarreta.