
Surf Forecasts:
Number Fours surf forecast from 6 Sep 2026:
- Most powerful swell: Tuesday 8 Sep, 2AM (local time) - 11ft (3.5m), 14s period, SW swell with 3,809 kJ wave energy.
Best Forecast Surf Conditions for Number Fours this week:
The most powerful waves expected at Number Fours in the next 16 days are 3.5m 14s and forecast to arrive on Tuesday (Sep 08) at 2AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 11s period and expected on Tuesday (Sep 08) at 2PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2AM (Tue 8th Sep) | 11ft (3.5m) 14s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, this is Rusty, and I’m looking at a sixteen-day run for Number Fours. Straight up, I gotta be honest with you—this isn’t going to be a week of classic, easy-going surf. There’s a lot of marginal window here, and some of the better-looking swell gets tangled up with tricky conditions.
The whole picture starts off a bit rough. We’ve got some energy coming through from the east-northeast, and a solid pulse shows on Saturday the 5th with a 7 ft swell from the ENE, period at 13 seconds. But that’s riding in with a fresh 19 mi/h cross-offshore wind. The water’s sitting at 81°F, bang on average for this time of year, so no surprises with the temp.
The combined swell energy is strong at this point, reading 2162, and it stays high through the weekend, peaking at 4705 late Monday the 7th. But here’s the kicker—those days are all carrying a “marginal” tag and conditions are often a bit lumpy or crossed up. Monday afternoon swings the swell direction to the southwest, which doesn't line up with the optimum SSE for Number Fours, making that swell a bit off-angle for the reef.
By Tuesday the 8th, we’ve got onshore southerly winds, and the quality drops. The forecast calls it poor, and I’m not paddling out in that. There’s a real gap here—nothing clean or recommended through the middle of the week.
Now, if you’re patient, there’s a brief window that looks top shelf. The standout is Monday the 14th. Check it out: Saturday the 12th and Sunday the 13th we’ve got small clean waves building, but Monday is the real gem. The morning has a 6 ft ENE swell, period at 8 seconds, and the wind is dead glassy at just 3 mi/h. Glassy! That’s rare, and it’s going to put a mirror on the face of Number Fours. The combined energy sits at 533, nothing crazy, but with those conditions, the reef will be clean and very surfable. This is the best on offer.
After that, the energy drops away fast. The second week sees smaller south-southwest swells rolling in, but they’re inconsistent and the wind picks up again. The 18th and 19th show a bit of life with longer 17-second groundswell from the SSW, around 4 ft, but this long-period stuff can be straight at a beach setup—though Number Fours is a reef, so it might hold better. Still, those days are only marginal.
For the short-term, forget it. The long wait is real, but that Monday the 14th glass-off session is worth circling on the calendar. It’s a solid bet for a clean, uncrowded morning at Number Fours, but keep in mind the reef can get a bit tricky if you’re not sharp.
Stay patient, keep an eye on that day, and I’ll see you out there if it holds.
Rusty.
Short Range ForecastModerate rain (total 18mm), heaviest on Sun night. Warm (max 27°C on Sat afternoon, min 25°C on Sat night). Mainly fresh winds. | Days 5-7 Weather SummaryLight rain (total 4mm), mostly falling on Tue afternoon. Warm (max 27°C on Tue afternoon, min 25°C on Thu night). Wind will be generally light. | |||||||||||||||||||
Sat 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | ||||||||||||||
PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map | ||||||||||||||||||||
Wave Height (m) Direction Period (s) | ENE 13 | ENE 13 | ENE 12 | ENE 12 | ENE 12 | ENE 13 | SW 15 | SW 14 | WSW 12 | ENE 11 | ENE 10 | SSW 14 | SSW 13 | SSW 13 | ENE 7 | ENE 7 | SW 16 | ENE 12 | ENE 12 | ENE 11 |
Wave Graph | ||||||||||||||||||||
1512 | 1430 | 1100 | 1437 | 1461 | 1497 | 2449 | 3809 | 1259 | 627 | 356 | 273 | 257 | 176 | 177 | 154 | 211 | 477 | 399 | 394 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross | cross-on | on | on | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 00:18AM0.21m | 1:00PM0.73m | 1:21AM0.26m | 1:47PM0.73m | 2:09AM0.32m | 2:28PM0.72m | 2:51AM0.39m | 3:05PM0.69m | 3:32AM0.45m | 3:39PM0.64m | 4:11AM0.50m | 4:12PM0.57m | 4:51AM0.54m | |||||||
Low Tide | 8:03PM0.13m | 5:11AM0.08m | 8:31PM0.10m | 6:25AM0.07m | 8:57PM0.08m | 7:26AM0.06m | 9:22PM0.06m | 8:21AM0.06m | 9:46PM0.05m | 9:12AM0.07m | 10:10PM0.04m | 10:02AM0.10m | 10:33PM0.04m | |||||||
— | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
6:43 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | — | 6:38 | — | — | 6:37 | — | |
mm | — | — | — | 3 | 6 | 3 | 2 | 2 | 2 | 2 | 2 | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 26 | 26 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 26 |
Feels °C | 26 | 26 | 25 | 27 | 26 | 28 | 28 | 27 | 27 | 28 | 30 | 30 | 29 | 26 | 26 | 26 | 25 | 26 | 26 | 25 |
Swell 1 Height (m) Direction Period (s) | S 12 | SSW 12 | ENE 12 | E 12 | ENE 12 | SW 14 | SW 15 | SW 14 | WSW 12 | SSW 9 | ENE 10 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | SSW 12 | ENE 13 | ENE 12 | ENE 12 | ENE 11 |
650 | 404 | 1100 | 1175 | 1461 | 1382 | 2449 | 3809 | 1259 | 405 | 278 | 173 | 149 | 157 | 177 | 123 | 170 | 477 | 399 | 394 | |
Swell 2 Height (m) Direction Period (s) | NNE 10 | SSW 16 | SSW 12 | SSW 12 | SSW 14 | SSW 17 | ENE 12 | ENE 12 | ENE 11 | ENE 11 | SSW 8 | SSW 14 | SSW 13 | SSW 13 | E 12 | E 12 | SW 16 | SW 16 | SW 15 | SW 15 |
19 | 166 | 374 | 647 | 1095 | 385 | 1405 | 1102 | 901 | 627 | 183 | 273 | 257 | 176 | 141 | 103 | 211 | 261 | 229 | 226 | |
Swell 3 Height (m) Direction Period (s) | NNE 10 | SSE 10 | SSW 16 | S 18 | S 18 | SSE 7 | SSW 17 | SSW 15 | SSW 15 | W 11 | SSW 14 | SSW 8 | E 13 | E 12 | SSW 13 | SW 18 | SSW 12 | SSW 12 | SSW 11 | SSW 11 |
19 | 19 | 318 | 174 | 246 | 57 | 625 | 500 | 474 | 496 | 356 | 83 | 163 | 146 | 131 | 154 | 81 | 45 | 43 | 24 | |
Wind waves Height (m) Direction Period (s) | ENE 13 | ENE 13 | — | ENE 12 | — | ENE 13 | SSE 8 | SSE 8 | S 10 | — | — | — | — | — | — | ENE 7 | ENE 7 | — | — | — |
1512 | 1430 | — | 1437 | — | 1497 | 226 | 238 | 627 | — | — | — | — | — | — | 154 | 140 | — | — | — | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 31 | 1 | 31 | 31 | 31 | 127 | 45 | 45 | 48 | 19 | 16 | 1 | 1 | 31 | 31 | 1 | 1 | 31 | 31 | 1 |
Best forecast wave conditions in Oahu | ||||||||||||||||||||
Best forecast wave conditions in United States | ||||||||||||||||||||
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Information about the Number Fours Surf forecast
The above surf forecast table for Number Fours provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Number Fours can be found by selecting the local surf guide option on the grey menu. Our Number Fours surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Number Fours) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Number Fours may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Number Fours is 5 km (3 miles) from Honolulu. If you plan a vacation in Oahu, look for hotels and other accommodation in Honolulu. Honolulu has rooms for a wide range of budgets as well as car hire and transport links.










