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Kahalu'u ratings
Quality on a good day: 3.3
Consistency of Surf: 4.7
Difficulty Level: 2.0
Wind and Kite Surfing: 1.0
Crowds: 1.7

Overall: 3.3

See all 18 ratings

Based on 3 votes. Vote


Surf Report Feed

Kahalu'u Swell Statistics, October: All Swell – Any Wind

This chart shows the variation of swells directed at Kahalu'u through a typical October. It is based on 2976 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the best grid node based on what we know about Kahalu'u, and at Kahalu'u the best grid node is 10 km away (6 miles).

The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 51% of the time. Green and yellow show increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how commonly that size swell occurs.

The diagram implies that the dominant swell direction, shown by the largest spokes, was W, whereas the the prevailing wind blows from the WNW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Kahalu'u and out to sea. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Kahalu'u, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause good for surfing waves at Kahalu'u run for about 49% 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.