Rivermouth_Wailuku Surf Forecast and Surf Report

Alright folks, Rusty here. Let’s cut through the data and talk about what’s really happening at Rivermouth_Wailuku. This is a reef setup, fairly consistent, and it's exposed to the swell. The water temp is sitting at 80°F with barely a wiggle from the norm, so nothing unusual there—just your standard warm summer bath.

Right off the bat, we’ve got a tough stretch. From Tuesday the 21st through to the end of the month, it’s a real mixed bag. The wind is mostly cross-on from the ENE, and the wave quality is being hammered by that. Through the 21st, 22nd, and 23rd, the swell is hanging around 3ft to 5ft, but the period is short—7 seconds or less—so it’s messy, weak, and just not doing anything for this reef. The combined energy is moderate (197 to 260), but it’s all cross-on chop. Not worth paddling out for.

The 24th and 25th don’t get much better. Swell bumps up to 6ft, but still cross-on, still short period, and the energy climbs a bit (292 to 471). The waves are there, but the wind is ruining the party. Then on the 26th, things get interesting for a moment. Swell jumps to 5ft to 5ft, and the period goes to 16 seconds—that’s a very long-period groundswell arriving from the east. The energy gets strong (1240 to 1370), but it’s still cross-on. That long period at a reef break could actually line up some nice lines, but the wind is just enough to spoil the surface. It’s a tease.

From the 27th to the 29th, the swell holds around 5ft to 7ft, and the period is still long (12 to 14 seconds). The wind shifts offshore from the NNE, which is a major positive. The energy is strong (1095 to 1250). This is when it starts to look rideable, but the forecast calls it “marginal.” The tide or something is off. Still, if you’re desperate, the mornings of the 28th and 29th with a light breeze might offer a few clean ones.

Now, here’s the standout. Thursday the 30th of July. Morning. That’s the one. The swell drops to a manageable 5ft from the NE, period is 10 seconds, but the wind is glassy—completely still. That’s the magic word. The energy is moderate (517), but the conditions are rated as “very good.” This is your best window. The reef will be clean, the wave shape should be solid, and the crowd might be around (it’s often busy), but for a Thursday morning, you might get lucky. Swell direction (NE) is a good match for this break’s optimum (NNE). This is the one to aim for.

After that, it’s back to the grind. The 31st through to the 2nd of August is cross-on chop again, with swell bouncing between 2ft and 5ft, and the period is short. Not good. The 3rd and 4th of August show a little more promise with a longer period (9 to 13 seconds) and swell up to 7ft, but the wind is still cross-on or onshore, and the energy is strong (853 to 1238). The 4th of August afternoon has a 7ft, 13-second swell from the ENE with onshore wind, which is a lot of water moving around but not clean. The 5th of August is more of the same—cross-on, 6ft, 12 seconds. It’s a long wait for another clean day, and that one on the 30th is the clear winner.

So to sum it up: the first week is a write-off thanks to the wind. The 26th has the power but not the wind. The 30th of July is your day—get in the water Thursday morning. After that, it’s a gamble until the 4th and 5th of August, but the wind needs to cooperate. Keep an eye on it.

Rusty.

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