
Surf Forecasts:
Number Fours surf forecast from 3 Sep 2026:
- Best quality surf: Monday 7 Sep, 2AM (local time) - 7ft (2.1m), 12s period, ENE swell with cross-offshore winds.
- Most powerful swell: Tuesday 8 Sep, 2PM (local time) - 16ft (5.0m), 14s period, SSW swell with 10,059 kJ wave energy.
- Next surfable swell (1★+): Monday 7 Sep, 2AM (local time) - 7ft (2.1m), 12s 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 (Sep 07) at 2AM. The primary swell is predicted to be 2.1m and 12s period with a secondary swell of 1.6m and 12s. 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 14s and forecast to arrive on Tuesday (Sep 08) at 2PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 6s period and expected on Monday (Sep 07) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Mon 7th Sep) | 7ft (2.1m) 12s |
| Best Surf | 2AM (Mon 7th Sep) | 7ft (2.1m) 12s |
| Most Powerful | 2PM (Tue 8th Sep) | 16ft (5.0m) 14s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s get into it. We’ve got a solitary spot on the radar for the next 16 days: Number Fours. It’s a reef set-up, so expect some defined lines when it’s on, but we’ve got a real mixed bag of weather and swell to wade through first.
The window opens on Wednesday the 2nd of September, and honestly, it’s a rough start. We’re looking at a 7ft swell from the ENE, but it’s getting hammered by a 25 mph cross-offshore breeze. The water is sitting at a warm 81°, which is about average for this time of year—nothing to complain about there. But the overall wave energy is weak (959), and the 8-second period is just too short and messy. This is a write-off for a paddle board. Honestly, with that wind and chop, it looks more like a kite-surfing setup than a clean surf session.
That same pattern of strong ENE wind and poor surf quality carries right through Thursday and into Friday morning. We’re looking at a 8ft swell on Thursday afternoon with a shocking 7-second period and 984 energy—just a big, lumpy mess. Don’t bother.
The first real glimmer of hope shows up on Friday the 4th of September. The swell drops to 4ft, but the direction swings to the S with a long 12-second period, and the energy jumps to a solid 1419. Problem is, the wind is still a fresh 22 mph cross-offshore, so it’s described as marginal. The same story plays out on Saturday and Sunday; the swell hangs around 7ft to 8ft from the ENE with a 12 to 14-second period, and the energy climbs into the 2000s and 2700s—that’s moderate to strong energy. But that persistent 15 to 18 mph cross-offshore wind is the spoiler. It’s clean, but the wind is just too strong for really good quality.
The standout moment arrives on Monday the 7th of September. The morning looks marginal, but the afternoon sees a 8ft swell from the ENE with a 13-second period. The combined energy hits a massive 5265—that’s strong, powerful surf. The wind is still a moderate 15 mph, but it’s cross-offshore. The forecast is still calling it “marginal” due to the risk of thunderstorms, so keep an eye on the sky.
Then things get ugly. Tuesday the 8th of September is a bust. A 15ft swell from the SW hits, but a near-gale 31 mph SSE wind is blowing straight onshore. The energy is a staggering 9725, but it’s a blown-out, dangerous mess. Leave your board at home.
We get a brief window of calm on Wednesday the 9th. The swell drops to 6ft from the SSW, the wind is a gentle 9 mph, and the energy is back to a moderate 672. It’s still only marginal, but it’s a step in the right direction.
The second week settles down, but it’s small. From the 10th to the 13th, we’re seeing waist-to-chest high swell (4ft to 5ft) from the ENE, with periods dropping back to 8-11 seconds. The winds are lighter, even going glassy on the afternoon of the 13th and the 14th. On Monday the 14th of September, we get a fascinating blip: a tiny 2ft swell from the SW with a ridiculously long 24-second period. The energy is 767, and it’s glassy. That’s a proper groundswell, but it’s so long-period it’s going to be very straight and fat here at the beach. It’s a novelty, not a day for a proper session.
The very last day on the 17th of September, Thursday afternoon, sees a small spike: a 6ft ENE swell with a 9-second period and 1385 energy. The wind is a moderate 15 mph cross-offshore. It’s on the cleaner side, but still marginal.
The Verdict: If you’re desperate, the best bet in the whole 16 days is probably Monday the 7th of September for the raw power (8ft, 13-second period, 5265 energy) despite the risk of storms. The second-best option is the glassy, clean, but small conditions on Sunday the 13th and Monday the 14th of September. For the rest of it, the wind is just too strong or the swell is too small to really get excited about.
Rusty, signing off.
Short Range ForecastSome drizzle, heaviest during Wed morning. Warm (max 26°C on Wed morning, min 25°C on Wed morning). Mainly strong winds. | Days 4-6 Weather SummaryModerate rain (total 16mm), heaviest on Sun night. Warm (max 27°C on Sun afternoon, min 23°C on Sun night). Winds increasing (light winds from the ESE on Sun night, strong winds from the SE by Mon night). | ||||||||||||||||||||
Wednesday 2 | Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | |||||||||||||||
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 7 | ENE 7 | ENE 7 | S 12 | E 14 | S 13 | ENE 14 | ENE 13 | ENE 13 | ENE 12 | E 12 | ENE 12 | ENE 13 | ENE 13 | SW 14 | SW 15 | SSW 13 | SSW 10 |
Wave Graph | |||||||||||||||||||||
487 | 502 | 627 | 440 | 588 | 498 | 513 | 569 | 620 | 1858 | 1467 | 1467 | 1336 | 1062 | 1180 | 1451 | 1886 | 2090 | 8588 | 7274 | 1225 | |
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 | cross-on | on | cross-on |
High Tide | 8:21AM0.59m | 6:54PM0.28m | 9:39AM0.62m | 7:57PM0.22m | 10:58AM0.66m | 10:35PM0.19m | 12:05PM0.69m | 00:18AM0.21m | 1:00PM0.73m | 1:21AM0.26m | 1:47PM0.73m | 2:09AM0.32m | 2:28PM0.72m | 2:51AM0.39m | |||||||
Low Tide | 3:38PM0.25m | 1:25AM0.06m | 6:22PM0.22m | 2:24AM0.08m | 7:30PM0.17m | 3:46AM0.09m | 8:03PM0.13m | 5:11AM0.08m | 8:31PM0.10m | 6:25AM0.07m | 8:57PM0.08m | 7:26AM0.06m | 9:22PM0.06m | ||||||||
6:15 | — | — | 6:15 | — | — | 6:15 | — | — | 6:15 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
— | 6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | |
mm | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | 5 | 2 | 5 | 4 | 4 | 3 | 6 |
Temp °C | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 27 | 26 | 25 | 25 | 27 | 27 | 27 | 27 |
Feels °C | 23 | 23 | 22 | 23 | 23 | 21 | 23 | 22 | 22 | 24 | 24 | 24 | 25 | 26 | 26 | 25 | 25 | 24 | 23 | 25 | 28 |
Swell 1 Height (m) Direction Period (s) | S 16 | S 16 | S 15 | S 15 | SSE 12 | SSE 12 | S 12 | S 12 | S 13 | S 12 | S 12 | ENE 13 | SSW 12 | E 12 | ENE 12 | ENE 13 | ENE 13 | SW 14 | SW 15 | SSW 13 | SSW 10 |
422 | 318 | 275 | 209 | 288 | 308 | 513 | 403 | 620 | 628 | 636 | 1467 | 876 | 1062 | 1180 | 1451 | 1581 | 2090 | 8588 | 7274 | 1225 | |
Swell 2 Height (m) Direction Period (s) | SSE 10 | S 11 | E 13 | E 13 | S 14 | E 14 | E 14 | E 14 | E 13 | SSW 17 | SSW 18 | SSW 12 | SSW 20 | SSW 12 | SSW 12 | SW 12 | SW 14 | ENE 12 | ENE 11 | ENE 11 | ENE 9 |
20 | 40 | 123 | 162 | 101 | 334 | 432 | 569 | 507 | 112 | 121 | 793 | 76 | 787 | 710 | 700 | 1288 | 1407 | 991 | 521 | 320 | |
Swell 3 Height (m) Direction Period (s) | SW 14 | E 14 | SSE 15 | SSE 12 | SW 13 | S 14 | SW 12 | SW 13 | N 11 | NNE 10 | NNE 10 | NNE 9 | SSW 16 | SSW 18 | SSW 18 | SSW 17 | SSW 17 | SSW 15 | E 14 | SSW 15 | WSW 10 |
30 | 66 | 93 | 94 | 7 | 100 | 6 | 27 | 10 | 20 | 19 | 15 | 425 | 193 | 344 | 498 | 510 | 402 | 146 | 370 | 356 | |
Wind waves Height (m) Direction Period (s) | ENE 8 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 14 | ENE 13 | — | ENE 12 | NNE 6 | — | — | ENE 13 | ENE 12 | — | — | — |
487 | 502 | 627 | 440 | 588 | 498 | 468 | 456 | 512 | 1858 | 1467 | — | 1336 | 34 | — | — | 1886 | 1807 | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 39 | 39 | 48 | 127 | 128 | 39 | 39 | 126 | 34 | 31 | 126 | 4 | 2 | 31 | 0 | 1 | 1 | 123 | 125 | 115 | 45 |
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.










