San Jose Rivermouth Surf Forecast and Surf Report

Alright, Rusty here. Let's get into it.

It’s gonna be a lean couple of weeks overall, with only one true standout that you’ll want to circle on the calendar. Right now, through the end of August, we’ve got small, clean-ish waves but nothing that’ll get the heart pumping. The water temp is sitting at a very unusual 89° – that’s nearly 7° warmer than normal for this time of year, so you’ll be surfing in bathwater. Most days the swell is running 2 ft to 4 ft from the SSW, with a long-period groundswell hanging in the 13-16 second range. That kind of period at the San Jose Rivermouth can make things a bit tricky – long period swells tend to unload fast and straight on a beach-and-river setup, so expect some closeouts and longer lulls between sets. The combined energy is moderate, sitting around 300 to 700 (moderate energy).

Monday afternoon (17th August) kicks us off with a clean 4 ft SSW swell, cross-off wind out of the WSW at 15 mph, so it’ll look tidy. But the surf is marginal – small and a bit inconsistent. Tuesday morning (18th) is a write-off with poor conditions, but Tuesday afternoon brings a risk of thunderstorms and light NNW wind at 3 mph, cross-off, with 4 ft SSW groundswell. That’s a glassy window, and the wave comment says “expect good surf conditions” – that’s your best bet this first week. Clean, small, fun for a longboard or a fish.

Wednesday through the weekend stays small (2 ft to 3 ft) with a mix of breezy onshore and clean windows. The combined energy drops to 300-400 range – weak to moderate. Nothing to get excited about. There’s a morning on Monday 24th with 2 ft SW swell and onshore wind – skip it. Monday afternoon (24th) cleans up with a cross-off WSW breeze at 15 mph, but it’s still only 2 ft. The energy is moderate (568).

Then we come to Friday 28th August. That’s the one. Friday afternoon rolls in with a solid 5 ft SSW groundswell at a long 18 seconds, and the combined energy jumps to 1668 (strong). Wind is a light WSW at 6 mph, cross-off, so it’s clean. The wave comment says “excellent surf conditions for experienced surfers.” That’s the standout. At 5 ft, that’s getting a bit heavy for beginners, and with that 18-second period, the sets will be powerful, with big gaps between them. Paddling out will be easier, but the wave itself is better suited to the rivermouth setup – expect it to lurch up and run. Crowds are possible here (often), so get in early. This is the only time in the whole 16 days where the swell, wind, and energy all come together.

Saturday 29th and Sunday 30th August still have some size (5 ft to 6 ft) but the wind shifts onshore or cross-on, and the conditions turn marginal. The energy stays strong (950-1500 range), but the wind messes it up. If you’re an experienced surfer, Saturday morning might still be worth a look with 6 ft and light onshore wind, but it won’t be as clean as Friday.

After that, the first few days of September serve up 5 ft to 6 ft SSW swells, but with onshore or cross winds and moderate chop. Not worth the paddle.

So the call: Friday 28th August afternoon at San Jose Rivermouth is your only true standout. Clean, decent size, and strong energy. Everything else is small, weak, or wind-affected. Don’t sleep on that Friday window.

Rusty.

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