
Surf Forecasts:
Number Fours surf forecast from 12 Aug 2026:
- Best quality surf: Monday 17 Aug, 8AM (local time) - 8ft (2.4m), 9s period, ENE swell with cross-offshore winds.
- Most powerful swell: Sunday 16 Aug, 2AM (local time) - 11ft (3.5m), 10s period, ENE swell with 2,493 kJ wave energy.
- Next surfable swell (1★+): Monday 17 Aug, 8AM (local time) - 8ft (2.4m), 9s 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 8AM. The primary swell is predicted to be 2.4m and 9s period with a secondary swell of 0.8m and 14s. Another secondary swell of 1.2m and 6s 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 3.5m 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 1.5m 6s period and expected on Wednesday (Aug 12) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8AM (Mon 17th Aug) | 8ft (2.4m) 9s |
| Best Surf | 8AM (Mon 17th Aug) | 8ft (2.4m) 9s |
| Most Powerful | 2AM (Sun 16th Aug) | 11ft (3.5m) 10s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s talk about what’s cooking at Number Fours.
We’ve got a bit of a slow start, honestly. The first few days are looking marginal – the swell is there, but it’s just not coming together for a proper session. We’re talking small, clean waves but nothing that’s gonna get the heart pumping. The water’s sitting at 81°, about average for this time of year, so no complaints there.
Tuesday the 11th sees a tiny 3ft SSW swell with a 14-second period, but the cross-off wind from the ENE at 35 km/h is keeping it tidy. The combined energy is moderate (524). It’s surfable, but you’d be scratching for a decent ride.
Wednesday the 12th and Thursday the 13th are more of the same: 3ft to 4ft, S to SSW swell, with periods dropping from 18 seconds down to 15. That’s long-period groundswell, so the sets will have some push, but the consistency is lacking. The wind stays cross-off, keeping things clean. Combined energy is still moderate, in the 800s.
Friday the 14th is a bit of a write-off. The afternoon session gets a 0 for poor conditions, so don’t bother.
Now, hold onto your board. Saturday the 15th is where things get serious. The morning brings an 8ft ENE swell with an 11-second period and a strong breeze at 45 km/h. The combined energy jumps to 1637 – that’s strong. This is expert territory. The afternoon pushes to 10ft, but with a risk of thunderstorms and the same strong wind, it’s a beast. Only for the brave.
Sunday the 16th is lumpy. We’ve got 10ft E swell, but the wind is cross-on, making it choppy and messy. Not your friend.
The standout of the forecast is Monday the 17th.
Monday morning is the real deal. The swell drops to a more manageable 7ft from the ENE, with a period around 9 seconds. The wind swings to a gentle breeze from the east, giving us a clean, cross-off wind. The combined energy is still strong at 1102. The forecast calls it “excellent surf conditions for experienced surfers.” This is your window. The swell direction (ENE) is a great match for what Number Fours likes. Get out there early.
After Monday, the week settles back into smaller, cleaner but ultimately unremarkable surf. The swell drops to 5ft and then 4ft, with short periods around 7 seconds. The wind is a steady cross-off from the ENE, but the energy is weak. It’s not going to be a total washout, but it’s not worth getting excited about.
Looking into the second week, things get interesting again around the 22nd of August. We see a return of some long-period SSW and S swells, with periods up to 19 seconds. The combined energy is moderate (around 600-650). The wind is still a moderate cross-off from the ENE. But the swell height is small, 2ft to 3ft. It’s a surf, but it’s a long way out and the confidence is lower. It’s a promise, not a guarantee.
So, bottom line: the best session is hands down Monday morning, August 17th. That’s the one to circle on the calendar. It’s a clean, powerful, groundswell that’s got the right direction and the right wind. Everything else is either too small, too windy, or too messy.
Keep it salty.
Rusty
Short Range ForecastMostly dry. Warm (max 27°C on Tue afternoon, min 25°C on Tue night). Mainly fresh winds. | Days 5-7 Weather SummaryHeavy rain (total 37mm), heaviest during Sat night. Warm (max 27°C on Sun afternoon, min 25°C on Fri night). Winds decreasing (gales from the ENE on Sat night, light winds from the ESE by Sun night). | |||||||||||||||||||
Tue 11 | Wednesday 12 | Thursday 13 | Friday 14 | Saturday 15 | Sunday 16 | Monday 17 | ||||||||||||||
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) | SSW 14 | S 20 | S 18 | S 18 | S 16 | S 16 | S 15 | S 15 | S 14 | ENE 8 | ENE 8 | ENE 11 | ENE 11 | ENE 10 | E 10 | ENE 10 | ENE 10 | ENE 9 | ENE 8 | ENE 8 |
Wave Graph | ||||||||||||||||||||
269 | 276 | 509 | 498 | 520 | 501 | 662 | 537 | 411 | 411 | 533 | 1403 | 1906 | 2493 | 1763 | 1513 | 2216 | 651 | 486 | 462 | |
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-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off |
High Tide | 3:35PM0.79m | 3:43AM0.31m | 4:13PM0.75m | 4:30AM0.36m | 4:48PM0.69m | 5:17AM0.40m | 5:22PM0.62m | 6:06AM0.44m | 5:54PM0.53m | 6:57AM0.47m | 6:24PM0.45m | 7:54AM0.49m | 6:52PM0.37m | |||||||
Low Tide | 10:40PM0.05m | 9:08AM-0.00m | 11:08PM0.04m | 9:58AM0.03m | 11:36PM0.04m | 10:49AM0.08m | 00:03AM0.04m | 11:43AM0.14m | 00:30AM0.05m | 12:43PM0.20m | 00:58AM0.06m | 1:59PM0.25m | 1:27AM0.08m | |||||||
— | — | 6:07 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:09 | — | — | |
7:04 | — | — | 7:02 | — | — | 7:02 | — | — | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 7:00 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | 1 | 14 | 12 | 4 | 4 | 2 | 1 | — |
Temp °C | 27 | 25 | 26 | 26 | 26 | 27 | 27 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 27 | 27 | 27 | 26 | 25 |
Feels °C | 25 | 23 | 23 | 23 | 24 | 24 | 24 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 24 | 26 | 28 | 29 | 26 | 24 |
Swell 1 Height (m) Direction Period (s) | SSW 14 | SSW 14 | S 18 | S 18 | S 16 | S 16 | S 15 | S 15 | S 14 | S 14 | S 14 | S 13 | S 13 | S 13 | S 13 | S 13 | ENE 10 | ENE 9 | ENE 8 | ENE 8 |
269 | 243 | 509 | 498 | 520 | 501 | 662 | 537 | 411 | 411 | 306 | 222 | 168 | 173 | 116 | 119 | 1808 | 651 | 486 | 365 | |
Swell 2 Height (m) Direction Period (s) | SSE 9 | S 20 | SSW 13 | SSW 13 | SSW 13 | SSW 12 | W 12 | W 11 | ESE 11 | W 12 | W 11 | W 11 | S 16 | S 18 | S 16 | S 16 | S 14 | S 14 | SSE 7 | S 13 |
16 | 276 | 218 | 218 | 222 | 113 | 11 | 10 | 25 | 11 | 21 | 9 | 79 | 56 | 133 | 127 | 246 | 268 | 158 | 170 | |
Swell 3 Height (m) Direction Period (s) | S 21 | SSE 9 | W 13 | W 12 | W 12 | W 12 | SW 19 | SW 18 | W 12 | SSW 18 | SSW 17 | SW 17 | W 13 | W 13 | W 12 | W 12 | S 16 | S 9 | S 14 | SSE 6 |
79 | 15 | 30 | 25 | 25 | 11 | 14 | 13 | 11 | 30 | 29 | 12 | 30 | 30 | 25 | 25 | 81 | 15 | 203 | 27 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 6 | ENE 7 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 11 | ENE 11 | ENE 10 | E 10 | ENE 10 | ENE 10 | SSE 7 | — | ENE 8 |
160 | 181 | 139 | 158 | 218 | 188 | 219 | 362 | 356 | 408 | 533 | 1403 | 1906 | 2493 | 1763 | 1513 | 2216 | 168 | — | 462 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 32 | 31 | 31 | 39 | 31 | 31 | 44 | 31 | 39 | 128 | 201 | 201 | 201 | 201 | 233 | 45 | 39 | 0 | 31 | 31 |
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.











