
Surf Forecasts:
Number Fours surf forecast from 12 Aug 2026:
- Best quality surf: Monday 17 Aug, 5AM (local time) - 6.5ft (2.0m), 8s period, ENE swell with cross-offshore winds.
- Most powerful swell: Sunday 16 Aug, 11AM (local time) - 16ft (5.0m), 11s period, E swell with 5,738 kJ wave energy.
- Next surfable swell (1★+): Monday 17 Aug, 5AM (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 5AM. The primary swell is predicted to be 2.0m and 8s period with a secondary swell of 0.9m and 15s. Another secondary swell of 1.1m 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 5.0m 11s and forecast to arrive on Sunday (Aug 16) at 11AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.6m 6s period and expected on Wednesday (Aug 12) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Mon 17th Aug) | 6.5ft (2.0m) 8s |
| Best Surf | 5AM (Mon 17th Aug) | 6.5ft (2.0m) 8s |
| Most Powerful | 11AM (Sun 16th Aug) | 16ft (5.0m) 11s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s shaping up for Number Fours over the next couple of weeks.
First off, I gotta be straight with you – the start of this run is a bit of a bummer. We’ve got a solid long-period groundswell rolling in from the S with a period of 18 seconds, pushing around 3 feet, but the numbers are saying it’s a marginal call. The wind is a fresh cross-off from the ENE at 30 km/h, which keeps the surface clean, but the overall wave energy is weak (892). It’s just not coming together for a proper session. That theme sticks around through Thursday and Friday morning: the swell bumps up a touch to 3 feet to 4 feet, but that’s a S swell, not the optimum SSE direction this reef likes, and the wind stays a bit too strong. The combined energy hangs in the moderate range (809 to 903), but it’s still not firing.
By Friday afternoon, things get ugly. The swell direction swings to the ENE and the period drops to a short 7-8 seconds. The wind is still a fresh to strong breeze, and the surf quality is poor. Saturday morning sees a real spike in size – we’re looking at 10 feet of ENE swell with a moderate period of 11 seconds, and the wave energy jumps into the strong category (2166). But don’t get excited. That’s a strong cross-off wind at 45 km/h, and for a reef break, that’s just messy. This is one for the experts only, if anyone at all. By Saturday afternoon, the wind is a near gale at 50 km/h, and the surf is poor. Sunday is a write-off: a 16 feet E swell from a risk of thunderstorms, with a strong cross-onshore wind. The wave energy is huge (6108), but it’s a stormy, choppy mess. That’s kite-surfing territory, not paddle surfing.
The first real standout window opens up on Monday, 17th August. The swell drops back to a manageable 6 feet from the ENE, period is short at 8 seconds, but the wind is a moderate cross-off at 20 km/h. The wave energy is still moderate (1074), and the score jumps up a notch. It’s clean, but the short period means it’ll be a bit fat and sectiony. The real diamond in the rough comes at the very end of the run.
The best swell on offer is the glassy SSW groundswell arriving on Monday, 24th August. After a few days of small, weak SSW swells around 2 feet, we finally get a clean 3 feet pulse from the SSW with a period of 13 seconds. And the wind? Dead glass. SSW at 5 km/h. The wave energy is moderate (488), and the conditions are expected to be good. This is a true standout for the mellow surfer who wants a clean, longboard-style wave on the reef. The water temperature is about average for the time of year, nothing wild.
Tuesday, 25th August, also sees some glassy patches in the afternoon with a 2 feet SSW swell, period 15 seconds. Another good call for the patient surfer. And Wednesday, 26th August, the afternoon session looks very good with a 2 feet S swell, period 17 seconds, and a clean cross-off breeze. The energy is moderate (525) and the conditions are expected to be very good.
In the second week, the pattern stays small but clean. The morning of 27th August sees a bit of a bump to 5 feet from the ENE, but the period is short and the wind picks up, so it’s marginal.
So, if you’re looking for the pick of the litter, mark your calendar for Monday, 24th August – that glassy SSW swell at Number Fours is the one. Tuesday afternoon is a close second. The rest is either too small, too windy, or too big and messy.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Thu morning, min 25°C on Tue night). Mainly strong winds. | Days 5-7 Weather SummaryHeavy rain (total 37mm), heaviest during Sat night. Warm (max 27°C on Sat afternoon, min 25°C on Fri night). Winds decreasing (gales from the ENE on Sat night, light winds from the ENE by Sun night). | ||||||||||||||||||
Wednesday 12 | Thursday 13 | Friday 14 | Saturday 15 | Sunday 16 | Monday 17 | ||||||||||||||
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) | S 20 | S 18 | S 18 | S 16 | S 16 | S 15 | S 15 | ENE 7 | ENE 8 | E 8 | ENE 11 | ENE 9 | E 9 | E 11 | E 9 | ENE 8 | ENE 8 | ENE 8 | ENE 7 |
Wave Graph | |||||||||||||||||||
276 | 509 | 498 | 520 | 501 | 662 | 537 | 444 | 502 | 775 | 1932 | 1701 | 1978 | 5738 | 1672 | 621 | 463 | 356 | 231 | |
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-on | cross-on | cross | cross-off | cross-off | cross-off |
High Tide | 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 | 20 | 8 | 5 | 3 | — | — | — |
Temp °C | 26 | 26 | 26 | 25 | 27 | 27 | 25 | 26 | 27 | 25 | 26 | 27 | 26 | 27 | 27 | 26 | 26 | 26 | 25 |
Feels °C | 25 | 24 | 23 | 23 | 24 | 24 | 23 | 23 | 24 | 22 | 23 | 23 | 22 | 25 | 26 | 27 | 29 | 26 | 23 |
Swell 1 Height (m) Direction Period (s) | 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 16 | S 13 | ENE 8 | ENE 8 | ENE 8 | S 13 |
243 | 509 | 498 | 520 | 501 | 662 | 537 | 411 | 411 | 306 | 222 | 168 | 176 | 333 | 160 | 621 | 463 | 356 | 222 | |
Swell 2 Height (m) Direction Period (s) | S 20 | SSW 13 | SSW 13 | SSW 13 | SSW 12 | W 12 | W 11 | W 12 | ESE 12 | W 11 | W 11 | W 13 | S 18 | W 12 | S 16 | SSE 7 | S 14 | S 14 | W 11 |
276 | 218 | 218 | 222 | 113 | 11 | 10 | 11 | 50 | 21 | 21 | 30 | 56 | 25 | 127 | 93 | 334 | 260 | 10 | |
Swell 3 Height (m) Direction Period (s) | SSE 9 | W 13 | W 12 | W 12 | W 12 | SW 19 | SW 18 | SW 18 | W 12 | SSW 17 | SW 17 | S 19 | W 13 | SSW 19 | W 12 | S 14 | SSE 6 | SSE 6 | WSW 5 |
7 | 30 | 25 | 25 | 11 | 14 | 13 | 12 | 11 | 29 | 12 | 65 | 30 | 37 | 25 | 246 | 20 | 13 | 2 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 6 | ENE 7 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 8 | E 8 | ENE 11 | ENE 9 | E 9 | E 11 | E 9 | SSE 7 | ENE 8 | — | ENE 7 |
181 | 165 | 141 | 194 | 195 | 227 | 373 | 444 | 502 | 775 | 1932 | 1701 | 1978 | 5738 | 1672 | 154 | 257 | — | 231 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 31 | 31 | 39 | 31 | 31 | 126 | 34 | 44 | 155 | 201 | 201 | 201 | 201 | 151 | 45 | 1 | 31 | 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.











