Surf Forecasts:
Number Fours surf forecast from 14 Aug 2026:
- Best quality surf: Monday 17 Aug, 2AM (local time) - 6.5ft (2.0m), 8s period, ENE swell with cross-offshore winds.
- Most powerful swell: Sunday 16 Aug, 2AM (local time) - 16ft (5.0m), 10s period, E swell with 4,737 kJ wave energy.
- Next surfable swell (1★+): Monday 17 Aug, 2AM (local time) - 6.5ft (2.0m), 8s period with ENE swell.
Best Forecast Surf Conditions for Number Fours this week:
The surf forecast for Number Fours over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Monday (Aug 17) at 2AM. The primary swell is predicted to be 2.0m and 8s period with a secondary swell of 1.0m and 7s. Another secondary swell of 0.8m and 14s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Number Fours in the next 16 days are 5.0m 10s and forecast to arrive on Sunday (Aug 16) at 2AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 7s period and expected on Wednesday (Aug 19) at 5PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Mon 17th Aug) | 6.5ft (2.0m) 8s |
| Best Surf | 2AM (Mon 17th Aug) | 6.5ft (2.0m) 8s |
| Most Powerful | 2AM (Sun 16th Aug) | 16ft (5.0m) 10s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s have a look at what’s on offer.
Well, mate, I gotta be straight with you – the next 16 days at Number Fours are a real mixed bag, and honestly, a bit of a struggle to find a clean window. The forecast starts on Friday, August 14th, and we’re looking at a pretty long stretch of poor or marginal conditions before we get anything worth paddling out for.
The biggest issue is the wind. We’ve got a persistent cross-off or cross-shore breeze from the ENE and E, often blowing a fresh to strong breeze. That’s going to keep the surface messy and bumpy. The swell is there, but it’s not doing us any favours. Early on, we’ve got a 7ft ENE swell with a short 8-second period, carrying moderate energy (963), but it’s just not clean. The wave comment says “poor surf conditions” and the score is a zero – that’s a hard pass.
The weekend of the 15th and 16th is a write-off. The swell jumps to 12ft, but that’s a near-gale wind and a cross-shore chop. That’s not surf, that’s survival. The combined energy is strong, over 1700 (1793), but it’s all messy. If you’re a kiteboarder, this might look interesting, but for us paddle surfers, it’s a no-go.
Things settle down a bit around Monday, August 17th, but it’s still marginal. The swell drops to 6ft, and the wind is a moderate cross-off, keeping the face clean. But the period is still short at 8 seconds, and the energy is moderate (712). The score is only a 1 out of 10. It’s surfable, but you’ll be working hard for not much reward.
The real standout, the only one worth circling on your calendar, is actually the afternoon of Saturday, August 22nd. That’s the one day the forecast says “expect good surf conditions”. The swell is small, just 2ft, coming from the SW with a very long 16-second period. That’s proper groundswell, and it’s hitting Number Fours, which is a reef break, so it’ll handle that long period well. The wind is a gentle cross-off from the ENE, keeping it clean. The combined energy is weak (375), but for a reef setup with that long period, the shape could be really fun. The water temperature is about average for this time of year, no major anomaly noted. Just keep in mind crowds are possible here, so you might have some company. This is the best on offer, no question.
After that, we’re back into a long run of poor conditions. The wind picks up again, and the swell is either tiny or blown out. The period from August 23rd right through to the end of the forecast on August 29th shows nothing but poor or marginal forecasts. The energies stay moderate, but the scores are all zero or one. The wind is a constant cross-off from the ENE, often fresh, keeping things messy.
So, to sum it up: the first week is a bust. The only real window is the afternoon of Saturday, August 22nd. It’s a small, clean, long-period groundswell at a reef break. That’s your best shot. Everything else is either too windy, too big and messy, or just plain flat.
Rusty.
Short Range ForecastHeavy rain (total 48mm), heaviest during Sun morning. Warm (max 27°C on Fri afternoon, min 24°C on Sun morning). Winds decreasing (gales from the ENE on Sat night, light winds from the ENE by Sun night). | Days 4-6 Weather SummarySome drizzle, heaviest during Mon morning. Warm (max 26°C on Mon morning, min 25°C on Mon morning). Mainly fresh winds. | ||||||||||||||||||||
Friday 14 | Saturday 15 | Sunday 16 | Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | |||||||||||||||
AM | 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 8 | ENE 8 | ENE 8 | ENE 9 | E 9 | E 10 | ENE 9 | ENE 9 | ENE 8 | ENE 8 | S 14 | ENE 7 | S 13 | S 13 | ENE 8 | SW 16 | E 8 | SW 16 | SW 18 | SSW 17 | SW 16 |
Wave Graph | |||||||||||||||||||||
494 | 604 | 1081 | 1556 | 2069 | 4737 | 1981 | 819 | 511 | 334 | 260 | 193 | 165 | 162 | 163 | 129 | 84 | 129 | 249 | 200 | 274 | |
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-off | cross | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 5:22PM0.62m | 6:06AM0.44m | 5:54PM0.53m | 6:57AM0.47m | 6:24PM0.45m | 7:54AM0.49m | 6:52PM0.37m | 8:59AM0.51m | 7:16PM0.30m | 10:13AM0.53m | 11:25AM0.56m | 10:11PM0.21m | |||||||||
Low Tide | 10:49AM0.08m | 00:03AM0.04m | 11:43AM0.14m | 00:30AM0.05m | 12:43PM0.20m | 00:58AM0.06m | 1:59PM0.25m | 1:27AM0.08m | 3:56PM0.27m | 2:01AM0.10m | 2:47AM0.12m | 8:27PM0.20m | |||||||||
6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:11 | — | — | 6:11 | — | — | |
— | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | |
mm | — | — | — | — | — | 8 | 27 | 7 | 6 | 1 | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 27 | 25 | 26 | 27 | 26 | 26 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 23 | 24 | 22 | 22 | 23 | 21 | 26 | 28 | 27 | 26 | 26 | 24 | 24 | 24 | 24 | 26 | 25 | 25 | 26 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | S 14 | S 14 | S 14 | S 13 | S 13 | S 14 | SSE 8 | ENE 9 | S 7 | S 14 | S 14 | S 13 | S 13 | S 13 | ENE 8 | E 8 | E 8 | E 8 | E 7 | E 8 | E 8 |
411 | 411 | 306 | 222 | 168 | 184 | 164 | 819 | 89 | 334 | 260 | 170 | 165 | 162 | 163 | 111 | 84 | 82 | 112 | 90 | 113 | |
Swell 2 Height (m) Direction Period (s) | W 12 | E 11 | W 11 | W 11 | W 13 | S 18 | S 16 | SSE 8 | S 14 | S 6 | S 6 | SSW 5 | SW 17 | SW 18 | S 13 | NNE 7 | NE 7 | NNE 7 | SW 18 | SSW 17 | SW 16 |
11 | 64 | 9 | 9 | 30 | 56 | 188 | 151 | 250 | 34 | 22 | 5 | 74 | 79 | 116 | 35 | 47 | 31 | 249 | 200 | 274 | |
Swell 3 Height (m) Direction Period (s) | SW 18 | W 12 | SW 17 | NNW 8 | S 19 | W 13 | SSW 12 | S 13 | S 16 | SW 18 | SSW 19 | W 11 | E 9 | SW 7 | SW 18 | SW 16 | S 12 | SW 16 | NNE 7 | NNE 7 | NE 7 |
12 | 11 | 12 | 6 | 65 | 30 | 49 | 163 | 81 | 50 | 37 | 10 | 26 | 11 | 79 | 129 | 45 | 129 | 30 | 29 | 23 | |
Wind waves Height (m) Direction Period (s) | ENE 8 | ENE 8 | ENE 8 | ENE 9 | E 9 | E 10 | ENE 9 | — | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | — | — | — | — | — | — | — |
494 | 604 | 1081 | 1556 | 2069 | 4737 | 1981 | — | 511 | 318 | 259 | 193 | 139 | 147 | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 39 | 48 | 130 | 156 | 201 | 156 | 128 | 46 | 0 | 31 | 31 | 31 | 31 | 31 | 1 | 1 | 1 | 1 | 31 | 1 | 1 |
Best forecast wave conditions in Oahu | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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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.











