Kahalu'u Surf Forecast and Surf Report

Alright folks, Rusty here. Let’s take a look at what’s shaping up for our local waters.

Right off the bat, we’ve got a really quiet start. The first week or so is pretty much all small stuff and marginal conditions. The real action, the standout window, doesn’t arrive until the second week of the forecast. There’s a big gap in the middle with a few days of nothing worthwhile, but then things get interesting.

We’re looking at Kahalu'u as the main spot. It’s a reef break, very consistent, and best for beginners when it’s small. The water temp is sitting at 82°F – that’s about 1°F warmer than normal for this time of year, so not a huge deal, just a touch on the warm side.

The first few days, from Saturday the 29th of August through to the end of the first week, are all tiny waves. We’re talking 1ft to 3ft most of the time, with a modest combined swell energy (around 260 to 574). The swell direction is mostly from the S or SSW, which is a bit off from the optimum W direction for this spot. The period is long, between 12 and 19 seconds, meaning it’s groundswell, but there just isn’t enough size to get excited about. Winds are light and variable, often cross or cross-onshore, which keeps the surface a bit bumpy. The scores are low, and honestly, it’s just a lot of marginal surf. Sunday afternoon the 30th does go glassy, but on 1ft, it’s barely a ripple.

That all changes come Tuesday the 8th of September. The swell starts to build on Monday the 7th, hitting 5ft by the afternoon with a combined energy of 787 – that’s a solid jump. Then Tuesday the 8th morning we see 5ft from the S with a period of 12 seconds, and the energy is up to 1045. It’s still cross-onshore, so not perfect. But then Tuesday afternoon? That’s the one. The wind goes glassy, the swell is 6ft from the SSW, 12-second period, and the combined energy hits 1347. That’s a strong, powerful pulse. The file says it’s excellent for experienced surfers, and I’m telling you, that’s our best call. Waves over 5ft get a bit much for the beginners, but for a solid intermediate or above, this is the session to aim for.

Wednesday the 9th keeps the energy going. Morning is 7ft from the SSW (14-second period, energy of 1422), but it’s cross-onshore. The afternoon, however, goes glassy again with 6ft and an energy of 1203. That’s another top-tier window. We also get Thursday the 10th with glassy conditions in the afternoon, 7ft from the S, and energy of 1197. That’s a big swell, so it’s expert territory only. At that size, the long period (11-12 seconds) will make for some powerful, roping lines off the reef.

After that, the swell drops off fast. Friday the 11th morning is still fun – 6ft from the SSW, glassy, with a 9-second period, which is a bit shorter and more manageable. Then it gets messy with strong winds and storms. By Saturday the 12th, it’s back to tiny, poor conditions.

So, to wrap it up: the first week is a write-off. The real deal is from Tuesday the 8th of September afternoon through to Thursday the 10th. That’s your window. Big, clean, powerful S-SSW groundswell with glassy conditions. If you can handle the size, it’s going to be special.

Rusty.

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