Backdoor 4 Surf Forecast and Surf Report

Alright, Rusty here. Let’s have a look at what’s coming down the pipe for this spot.

Alright, so the window opens on July 6th with a wild spike in energy. We’ve got a big, powerful SSE swell hitting Backdoor 4 (Oahu), with combined energy readings right up in the very strong range (1729). The issue? This swell is way too big for a comfortable paddle – we’re talking 9.8 ft surf from the SSE. The wind is a fresh offshore from the SSE, which would usually be mint, but at this size, it’s really only for the absolute guns. Water temp is sitting at 66.4°, which is pretty average for this time of year, nothing weird there.

July 7th is much the same story – the swell actually builds a touch more to 11.5 ft, with the energy climbing to 2904 on Tuesday afternoon. Still a strong offshore wind from the south, so the wave face will be clean, but frankly, it’s too big for most. This sets up to be a bit of a washing machine for anyone not in the top tier.

Now, July 8th sees it drop a bit, down to 8.2 ft on the Wednesday morning, still with a clean offshore. It’s still on the big side for a lot of crews, but it’s getting into the realm of solid, heavy waves for strong intermediates if they’re feeling brave.

Things start to get interesting on July 9th. The swell drops to a much more manageable 4.9 ft on the Thursday morning, coming from the ESE with an 11-second period – that’s a nice, clean groundswell. The wind is light and cross-offshore, which means the waves will be holding their shape. The real gem is Thursday afternoon: the wind goes glassy, nearly dead calm, and the swell is 6.2 ft from the SE. That is a proper window for some clean, fun waves. The energy is still moderate (664), but for a reef break like this, that glassy afternoon is the standout of the first week.

Friday July 10th keeps it clean with chest to head-high sets, light cross-off winds, and a nice 10-second period. No complaints there.

From Saturday July 11th through to July 15th the quality falls away fast. The swell drops under 3.9 ft, the wind gets cross-shore and messy, and the energy drops into the weak zone. It’s a proper dead period for about five days. You’ll see a small blip on July 14th with a 3.3 ft, glassy afternoon swell from the south, but it’s a very short-lived option.

Here’s the second standout: July 16th Thursday afternoon. This one comes back with a punch. We get a 6.6 ft swell from the south, 7-second period (so a little short-period), but with a moderate offshore wind from the SSW. The energy jumps back up to 366, making it a solid session for the second week.

But the real beast returns on July 17th. Friday morning: glassy conditions, a 7.9 ft S swell with an 11-second period, and energy rocketing to 1344. The wind is dead calm. That’s going to be a serious, powerful wave. It’s big, so again, for experts only, but glassy conditions on a reef with that kind of groundswell energy? That’s a session you remember.

After that, July 18th through to July 21st is a mixed bag of onshore winds, dropping swell, and messy conditions. July 21st has another huge spike back up to 11.5 ft and very strong energy (2684), but it’s lumpy and cross-shore. Not the clean power of the 17th.

So, the clear winners are the glassy afternoon on July 9th for a clean, fun session, and the beast of a morning on July 17th for the big-wave crew. Watch the crowd factor at Backdoor 4 though – it’s a spot that can get busy, and when it’s good, it’s a magnet.

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