
Surf Forecasts:
Number Fours surf forecast from 6 Sep 2026:
- Most powerful swell: Monday 7 Sep, 11PM (local time) - 11ft (3.5m), 14s period, SW swell with 4,527 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 3.5m 14s and forecast to arrive on Monday (Sep 07) at 11PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.7m 11s period and expected on Tuesday (Sep 08) at 2PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11PM (Mon 7th Sep) | 11ft (3.5m) 14s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s talk about what Number Fours has in store for us.
Alright, the outlook for Number Fours is a bit of a mixed bag over the next two and a half weeks. We start off with some size, but the winds and conditions are a real letdown for the first week. The real standout window is going to be later on.
The water temperature at Number Fours is 81°, which is pretty much bang on average for this time of year.
Our first bit of hope comes around Sunday the 6th of September. We’ve got a solid 7ft swell from the ENE with a period of 12 seconds, so there’s a decent amount of energy in the water. But, a fresh cross-offshore wind at 19 mph is going to keep things a little bumpy. It’s clean enough, but the report flags it as marginal. Monday the 7th sees the swell bump up to 8ft from the ENE with a period of 12 seconds and moderate cross-shore winds, creating a cross-chop. That’s getting a bit full-on, and the conditions are just messy. By Tuesday the 8th, it’s onshore and lumpy. This stretch from Sunday through to Tuesday is honestly more of a kite-surfing setup than a clean paddle session.
Things start to drop off dramatically after that. From Wednesday the 9th through to Thursday the 17th, the swell is mostly tiny, often below 3ft, with very long-period groundswell in the 14 to 22 second range. While that long period means good shape and easy paddling out, the size is just too small for a proper session at a reef. We’ve got a lot of clear skies and cross-offshore winds, but the energy is weak. There’s a real dry spell there for over a week.
Now, here’s the one to keep an eye on. Thursday the 17th of September morning, we finally get a pulse back. Swell jumps to 8ft from the east with a period of 8 seconds. That’s a short-period wind swell, but it’s got some punch. It’s a solid size for intermediates, and the wind is a moderate cross-offshore from the ENE at 16 mph, keeping things clean. Friday the 18th is similar, with 7ft from the east and clean cross-off winds. This is the best window in the whole forecast. It’s not perfect, but it’s the biggest, cleanest swell we get. For the intermediate crew, this is your time. The reef at Number Fours should be handling that east swell nicely.
Crowds are possible here, so get in early if you can.
Overall, a quiet start and a long middle, but that Thursday and Friday around the 17th and 18th of September is the one to circle on the calendar. It’s a long way out, so keep an eye on it, but it’s our best bet by far.
Rusty.
Short Range ForecastHeavy rain (total 36mm), heaviest during Sun night. Warm (max 28°C on Tue afternoon, min 25°C on Sun night). Winds decreasing (fresh winds from the SE on Mon night, light winds from the SSE by Tue night). | Days 4-6 Weather SummaryLight rain (total 3mm), mostly falling on Wed afternoon. Warm (max 27°C on Wed morning, min 25°C on Thu night). Mainly fresh winds. | ||||||||||||||||||||
Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | |||||||||||||||
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 12 | ENE 12 | ENE 12 | ENE 12 | SW 14 | SW 13 | WSW 11 | ENE 11 | ENE 10 | SSW 14 | SSW 13 | SSW 13 | SSW 16 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 10 | ENE 10 | ENE 6 |
Wave Graph | |||||||||||||||||||||
1240 | 1064 | 1461 | 1703 | 1812 | 3799 | 883 | 604 | 356 | 269 | 257 | 176 | 179 | 158 | 211 | 261 | 256 | 234 | 445 | 439 | 190 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross | cross-on | cross-on | on | on | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 1:00PM0.73m | 1:21AM0.26m | 1:47PM0.73m | 2:09AM0.32m | 2:28PM0.72m | 2:51AM0.39m | 3:05PM0.69m | 3:32AM0.45m | 3:39PM0.64m | 4:11AM0.50m | 4:12PM0.57m | 4:51AM0.54m | 4:42PM0.50m | ||||||||
Low Tide | 8:31PM0.10m | 6:25AM0.07m | 8:57PM0.08m | 7:26AM0.06m | 9:22PM0.06m | 8:21AM0.06m | 9:46PM0.05m | 9:12AM0.07m | 10:10PM0.04m | 10:02AM0.10m | 10:33PM0.04m | 10:52AM0.13m | 10:56PM0.05m | ||||||||
6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
— | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | — | 6:38 | — | — | 6:37 | — | — | 6:37 | — | |
mm | — | 3 | 11 | 4 | 4 | 7 | 4 | — | 3 | — | 1 | 1 | 1 | — | — | — | — | — | — | — | — |
Temp °C | 27 | 27 | 26 | 26 | 27 | 27 | 27 | 28 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 26 | 27 | 26 | 26 | 28 | 26 | 28 | 31 | 30 | 31 | 30 | 27 | 27 | 25 | 24 | 25 | 24 | 23 | 25 | 24 | 23 |
Swell 1 Height (m) Direction Period (s) | ENE 12 | ENE 12 | ENE 12 | SW 14 | ENE 12 | SW 13 | WSW 11 | ENE 11 | ENE 10 | ENE 8 | ENE 8 | E 12 | E 12 | E 12 | E 11 | SW 16 | SW 15 | SW 15 | SW 15 | SSW 16 | SSW 13 |
1240 | 1064 | 1461 | 1273 | 1461 | 3799 | 883 | 604 | 325 | 173 | 161 | 153 | 141 | 101 | 127 | 261 | 232 | 178 | 191 | 99 | 68 | |
Swell 2 Height (m) Direction Period (s) | SSW 12 | SSW 12 | SSW 14 | SSW 17 | SW 14 | ENE 12 | SSW 9 | SSW 8 | SSW 8 | SSW 14 | SSW 13 | SSW 13 | SSW 13 | SSW 13 | SW 16 | SSW 12 | SSW 12 | SSW 11 | SSW 11 | SSW 13 | SW 16 |
374 | 517 | 1193 | 385 | 1812 | 950 | 510 | 306 | 138 | 269 | 257 | 176 | 129 | 93 | 211 | 45 | 46 | 25 | 23 | 70 | 64 | |
Swell 3 Height (m) Direction Period (s) | SSW 16 | S 19 | S 18 | SSE 8 | S 9 | SSW 15 | ENE 11 | W 10 | SSW 14 | SSW 8 | E 13 | SSW 8 | SSW 16 | SW 18 | S 12 | SW 9 | SW 8 | SW 8 | WSW 8 | SSW 11 | SE 8 |
318 | 180 | 243 | 67 | 186 | 494 | 680 | 432 | 356 | 98 | 166 | 32 | 179 | 155 | 72 | 20 | 11 | 10 | 6 | 11 | 2 | |
Wind waves Height (m) Direction Period (s) | — | ENE 12 | — | ENE 12 | SSE 8 | SSE 8 | — | — | — | — | — | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 10 | ENE 10 | ENE 6 |
— | 706 | — | 1703 | 486 | 438 | — | — | — | — | — | 147 | 172 | 158 | 186 | 249 | 256 | 234 | 445 | 439 | 190 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 31 | 31 | 7 | 130 | 58 | 79 | 26 | 19 | 16 | 19 | 1 | 1 | 1 | 1 | 1 | 4 | 31 | 31 | 2 | 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.










