Conditions at Hokkaido in December
December: Cold Offshore Winds and Short-Period Waves
December marks the full arrival of winter and the return of the Siberian High. The wind rose is tilted hard toward WNW (21%), W (14.6%), NW (14.5%) and NNW (13.7%), giving the SSW-facing beach plenty of offshore flow. However, the average wave period has fallen to 6.9s, and the swell spectrum is dominated by WSW (18.3%), W (16.2%), SW (11.5%) and S/SSW energy. These are short-period, cold-water windswells. Ideal conditions register only 11% of the time, usually when a low in the Sea of Japan sends S/SW energy while a continental high keeps the wind offshore. Water temp is 8.7°C, air temp hovers near -0.1°C and snow is often in the forecast. The waves are generally 2-3ft (0.9m) and quick, but the best December windows can supply surprisingly fun, hollow little waves.
Average Spot conditions at Hokkaido in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Hokkaido 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 Hokkaido for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Hokkaido 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 Hokkaido.