
Surf Forecasts:
Number Fours surf forecast from 15 Sep 2026:
- Most powerful swell: Thursday 17 Sep, 11AM (local time) - 7ft (2.1m), 10s period, ENE swell with 782 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 2.1m 10s and forecast to arrive on Thursday (Sep 17) at 11AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 6s period and expected on Wednesday (Sep 16) at 11PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11AM (Thu 17th Sep) | 7ft (2.1m) 10s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, folks. Rusty here, breakin’ down Number Fours for the next couple of weeks. Gotta level with ya—it’s a tough stretch, and you’ll be huntin’ for a good one.
Overall Picture:
We got some long-period groundswell tryin’ to sneak in from the southwest, but the wind’s stuck out of the east-northeast, blowin’ cross-off. The swell heights are small, and the wave quality keeps gettin’ called “marginal.” We hit a flat spell from the 20th through the 22nd—three days of poor conditions, not worth your time. The combined energy moves from moderate to strong at times, but the short-period windswell just ain’t shapin’ up.
The Play-by-Play:
Tuesday 15th & Wednesday 16th:
Small start. Tuesday morning has a 2.3 ft swell from the SW with a very long 20-second period. Water’s 81°F, right on average for this time of year. Wind is a moderate 12 mph cross-off. The combined energy reads 490 (moderate). It’s a reef break, fairly consistent, exposed to the swell, and it loves it from the SSE—so that SW direction is off. You’ll be scratchin’. Wednesday has 3 ft, period drops to 18 seconds, energy jumps to 807, but wind cranks to 19 mph. Marginal.
Thursday 17th:
First real size: 6.9 ft from the ENE, but the period is a weak 10 seconds. Energy hits 1207 (very strong). This one’s for experts only, but the short period and 22 mph cross-off wind make it a chunky, bumpy mess. Skip it.
Friday 18th – Monday 21st:
Friday drops to 3.3 ft, but energy stays strong at 1101 from a 17-second SSW groundswell. Wind is howlin’ at 25 mph by afternoon. Saturday holds similar size and period, energy a bit lower at 852. Then the doldrums hit: Sunday the 20th through Monday the 22nd sees 6.6 ft of short-period ENE slop with 25 mph winds. Combined energy in the 700s, but it’s “poor surf conditions.” Don’t bother.
Tuesday 22nd:
Wind drops slightly to 25 mph, swell angles more east, period hits 9 seconds, energy 1046. Still “marginal.” Not a standout.
Wednesday 23rd:
One to note. Wind eases to 16 mph from the east, swell holds at 6.9 ft from the east with a 10-second period. Energy is a meaty 1182. Downside? The wind shifts to a true cross-shore, bringin’ a cross-chop. That’ll mess up the face. It’s a B- option.
Thursday 24th & Friday 25th:
Thursday has 5.9 ft at 9 seconds, energy 841, with a fresher wind—still marginal. Friday 25th afternoon is our best window. The swell drops to 2.6 ft, but it’s a long-period 15-second SSW groundswell. Wind drops to a gentle 9 mph cross-off breeze. Combined energy is 556 (moderate). The wave comment says “very good surf conditions.” That’s your session. The swell direction ain’t ideal, but clean conditions and proper groundswell make it the best on offer.
Saturday 26th – Sunday 27th:
Saturday morning gets a light 6 mph cross-on breeze with 3 ft SSW swell at 15 seconds, energy 780. Decent but onshore. Sunday drops to 3 ft, 9 mph cross-off, energy 486. Fine, but nothin’ special.
Monday 28th – Tuesday 29th:
Monday is tiny (2-2.3 ft) and messy. Tuesday 29th afternoon is another little gem: 2.6 ft, 16-second SSW groundswell, light 6 mph cross-off breeze, energy 354, and “good surf conditions.” Small, but clean as a whistle. Worth a quick paddle.
Wednesday 30th:
Winding down. 2.3 ft, 15-second period, but wind picks up to 19 mph cross-off, energy drops to 252. Poor conditions.
The Pick of the Litter:
Circle Friday 25th September afternoon. That 2.6 ft, 15-second groundswell with light wind is gonna give you clean, glassy reef waves. It’s tiny but fun. Tuesday 29th September afternoon is a solid backup—same vibe, small and clean. Nothin’ else in the window is worth
Short Range ForecastLight rain (total 9mm), mostly falling on Thu night. Warm (max 27°C on Tue morning, min 26°C on Tue morning). Mainly fresh winds. | Days 4-6 Weather SummaryMostly dry. Warm (max 27°C on Fri morning, min 25°C on Sat night). Mainly strong winds. | ||||||||||||||||||||
Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | Monday 21 | |||||||||||||||
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) | SW 20 | SW 19 | SSW 19 | SW 18 | SSW 18 | SW 17 | ENE 10 | ENE 9 | SSW 18 | SSW 17 | SSW 17 | SSW 16 | SSW 16 | SSW 16 | E 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 8 |
Wave Graph | |||||||||||||||||||||
392 | 384 | 470 | 455 | 541 | 429 | 782 | 592 | 644 | 622 | 580 | 539 | 382 | 387 | 400 | 362 | 373 | 447 | 403 | 414 | 449 | |
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-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 6:07PM0.30m | 7:59AM0.57m | 6:32PM0.25m | 9:10AM0.56m | 7:25PM0.21m | 10:27AM0.57m | 11:01PM0.21m | 11:34AM0.59m | 00:19AM0.23m | 12:26PM0.61m | 00:59AM0.27m | 1:06PM0.62m | 1:32AM0.32m | ||||||||
Low Tide | 2:03PM0.23m | 00:07AM0.11m | 4:06PM0.24m | 00:38AM0.13m | 7:14PM0.21m | 1:26AM0.16m | 7:23PM0.18m | 2:56AM0.18m | 7:43PM0.16m | 4:35AM0.17m | 8:01PM0.15m | 5:47AM0.16m | 8:17PM0.13m | ||||||||
6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
— | 6:34 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — | — | 6:29 | — | — | 6:28 | — | |
mm | — | — | — | — | — | — | — | 2 | 7 | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 26 | 26 | 26 | 26 | 25 | 26 | 27 | 26 |
Feels °C | 28 | 28 | 27 | 26 | 26 | 26 | 26 | 27 | 26 | 24 | 24 | 24 | 25 | 23 | 24 | 24 | 22 | 22 | 24 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | SW 20 | SW 19 | SSW 19 | SW 18 | SSW 18 | SW 17 | SW 16 | SSW 16 | SSW 18 | SSW 17 | SSW 17 | SSW 16 | SSW 16 | SSW 16 | SSW 16 | S 16 | SSW 15 | SSW 14 | SSW 14 | S 14 | S 13 |
392 | 384 | 470 | 455 | 541 | 429 | 258 | 322 | 644 | 622 | 580 | 539 | 382 | 387 | 350 | 239 | 300 | 350 | 265 | 232 | 168 | |
Swell 2 Height (m) Direction Period (s) | NNE 8 | E 12 | NNE 8 | SW 12 | E 10 | E 10 | SSW 20 | SSW 19 | WSW 8 | SSE 9 | SSE 7 | SSE 7 | SSW 18 | S 18 | SW 16 | SSW 15 | SW 15 | SW 15 | SW 14 | SW 13 | SW 13 |
36 | 68 | 32 | 35 | 100 | 125 | 149 | 210 | 7 | 7 | 18 | 21 | 108 | 99 | 121 | 146 | 104 | 33 | 52 | 46 | 46 | |
Swell 3 Height (m) Direction Period (s) | E 12 | SW 12 | E 11 | S 6 | SW 11 | SW 11 | SW 11 | SSW 10 | SSE 10 | W 9 | W 9 | S 20 | SSE 6 | SSE 6 | SSW 14 | SSE 8 | W 13 | W 12 | W 13 | W 11 | W 12 |
46 | 38 | 58 | 3 | 31 | 19 | 18 | 10 | 9 | 6 | 6 | 67 | 12 | 13 | 37 | 6 | 3 | 11 | 13 | 10 | 11 | |
Wind waves Height (m) Direction Period (s) | ENE 8 | NE 8 | ENE 5 | ENE 10 | NE 5 | NE 6 | ENE 10 | ENE 9 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | E 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 8 |
52 | 71 | 51 | 314 | 100 | 203 | 782 | 592 | 606 | 472 | 427 | 416 | 350 | 359 | 400 | 362 | 373 | 447 | 403 | 414 | 449 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 1 | 2 | 31 | 31 | 31 | 31 | 33 | 31 | 39 | 42 | 39 | 31 | 39 | 32 | 39 | 42 | 31 | 34 | 39 | 34 |
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.










