Waimea Rivermouth Surf Forecast and Surf Report

Alright folks, Rusty here. Let’s talk about what’s on the menu for the next couple of weeks at Waimea Rivermouth. Don’t get too excited for the first few days, but there’s some real firepower coming.

We start off on Friday, September 4th, with a clean 4 ft SSE swell rolling in. The water’s sitting at a warm 81°, which is about average for this time of year. The wind is a gentle cross-off from the ENE, keeping things tidy. Combined swell energy is moderate (729). It’s a friendly, manageable size for the beginner-friendly setup here, but nothing to write home about yet. The crowds are *sometimes* an issue here, so you might have a few out.

Saturday morning, September 5th, the swell pushes up to 5 ft from the S with a 12-second period, still clean with that cross-off breeze. The energy is still moderate (737). It’s picking up.

Then, Saturday afternoon, things get interesting. The swell jumps to 7 ft from the E with a 13-second period, and the combined energy rockets up to 2328 – that’s strong stuff. The wind stays gentle cross-off. This is the first standout. It’s getting into the zone where it’s better for experienced surfers, but the quality is excellent.

Sunday morning, September 6th, keeps the energy high with a 6 ft S swell and 2449 energy, again clean. But Sunday afternoon, the wind swings cross-shore from the ESE with some light rain, and the quality drops – things get a bit choppy.

Now, listen up. Monday, September 7th, is for the brave and the expert only. The morning brings a massive 15 ft S swell with a 16-second period, and the energy is a colossal 12126. The wind is cross-off, so it’s clean, but 15 ft is way too big for this spot. This is a bomb. By the afternoon, it’s a 23 ft S swell with near gale-force winds – total chaos. Don’t even think about paddling out. This setup is more interesting for kite surfing than paddle surfing.

After that, the swell drops hard. Tuesday, September 8th, the wind goes onshore, and the swell is down to 3 ft. Not great. Wednesday, September 9th, is glassy with a tiny 3 ft SSW swell – clean but small. We get a bit of a run of small, clean days from the 9th to the 11th, with E swells around 4 ft to 5 ft, and periods of glassy conditions. The energy is weak to moderate. It’s fun, but not the main event.

There’s a gap of a few days of small, ordinary surf from the 12th to the 14th. September 14th is particularly poor, with only 1.0 ft SSW swell and weak energy.

The next real standout comes on Tuesday, September 15th. The afternoon brings a 7 ft E swell with a 9-second period, and the energy is strong at 1080. The wind is light and cross-off, making for excellent conditions for experienced surfers.

Then, Wednesday, September 16th afternoon, we get a glassy 7 ft E swell with a 9-second period and 1031 energy. This is another top pick. The glassy conditions will make it smooth as butter.

The final run of the forecast, from Thursday, September 17th, through Saturday, September 19th, is a real treat. We get glassy conditions with a very long-period SSW groundswell, 16 to 17 seconds, and clean, peeling waves. The swell is only 3 ft to 3 ft, but that long period (over 15 seconds) means it’s a proper groundswell. For a rivermouth, that long period is perfect – it’ll set up beautifully. The energy is moderate (530-798). It’s a classic, mellow, high-quality session.

So, the two real standouts: Saturday, September 5th afternoon through Sunday morning, September 6th, for the powerful, clean E and S swells. And the glassy, long-period groundswell from Thursday, September 17th, through Saturday, September 19th, which is a dream for a rivermouth setup.

Rusty out.

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