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Onjuku ratings
Quality on a good day: 3.0
Consistency of Surf: 3.3
Difficulty Level: 2.3
Wind and Kite Surfing: 4.0
Crowds: 3.0

Overall: 3.8

See all 18 ratings

Based on 3 votes. Vote


Surf Report Feed

Onjuku Swell Statistics, September: All Swell – Any Wind

The graph illustrates the variation of swells directed at Onjuku through an average September and is based upon 2880 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Onjuku. In this particular case the best grid node is 24 km away (15 miles).

The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 39% of the time. Green and yellow show increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell occurs.

The diagram suggests that the prevailing swell direction, shown by the biggest spokes, was SE, whereas the the most common wind blows from the ESE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Onjuku and out to sea. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Onjuku, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause surfable waves at Onjuku run for about 61% of the time.

IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.