
Surf Forecasts:
Number Fours surf forecast from 4 Sep 2026:
- Best quality surf: Wednesday 9 Sep, 5AM (local time) - 3ft (0.9m), 14s period, SSW swell with cross-offshore winds.
- Most powerful swell: Monday 7 Sep, 5PM (local time) - 13ft (4.0m), 14s period, SW swell with 6,058 kJ wave energy.
- Next surfable swell (1★+): Wednesday 9 Sep, 5AM (local time) - 3ft (0.9m), 14s period with SSW 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 Wednesday (Sep 09) at 5AM. The primary swell is predicted to be 0.9m and 14s period. 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 4.0m 14s and forecast to arrive on Monday (Sep 07) at 5PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 9s period and expected on Wednesday (Sep 09) at 5AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Wed 9th Sep) | 3ft (0.9m) 14s |
| Best Surf | 5AM (Wed 9th Sep) | 3ft (0.9m) 14s |
| Most Powerful | 5PM (Mon 7th Sep) | 13ft (4.0m) 14s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Looks like Number Fours is the only game in town for the next couple of weeks, and I gotta be honest—it’s a mixed bag. We’ve got some real windows of fun surf, but plenty of days where you’ll be scratching your head. The water’s sitting at a comfortable 27°, which is pretty much average for this time of year, nothing weird going on there.
First up, Friday the 4th of September. The swell’s small, around 1.3m from the S, with a 12-second period and the combined energy reading 1327—moderate energy, nothing to get too excited about. Wind’s a stiff 40 km/h cross-off from the ENE, which will keep things reasonably clean, but the wave comment calls it marginal. Honestly, it’s not doing much for me.
Saturday the 5th bumps up a bit—2.3m from the ENE, period 13 seconds, energy jumping to 2469. Still, the wind is cross-off at 30 km/h and the model’s not rating it. It’s surfable but not a standout. Same story carries through Sunday and into Monday.
Now, Monday the 7th of September morning—this is where it gets interesting. We’ve got 3.0m of swell from the SW, long 15-second period, and the combined energy is 6398—that’s strong wave energy. The wind is cross-shore from the ESE at 20 km/h, and the wave comment says it’s clean-ish but with a cross-chop. This is your best window in the first week, but it’s solidly in the expert-only zone at that size, especially on a reef break. Afternoon blows up to 4.0m with cross-onshore wind—that’s just messy and no good for paddling.
After that, the early part of the second week fades fast. Tuesday the 8th and Wednesday the 9th see the swell drop to 1.5m and under, with onshore winds on Tuesday and light cross-off on Wednesday. Not much happening.
The second week starts to look promising again from around the 13th of September. We get a run of 2.1m to 2.3m from the ENE, with periods around 8 to 9 seconds—so shorter period, more windswell than groundswell. However, the wind stays cross-off and light to moderate, keeping it clean. By Wednesday the 16th of September morning, the forecast calls it “excellent surf conditions for experienced surfers”—2.2m from the ENE, light breeze from ENE at 10 km/h, energy at 1360. That’s a solid session for someone who knows what they’re doing.
The best true standout, though, has to be Wednesday the 16th. Clean conditions, manageable size for intermediates with some experience, and consistent lines. Crowds are “sometimes” a factor here, so you might have company, but with conditions that clean, it’s worth it.
Thursday the 17th brings a change—swell drops to 0.9m but it’s a long-period SSW groundswell at 17 seconds, energy around 1010. That’s the kind of long-period swell that’ll wrap into a reef like Number Fours beautifully, but it’s small. If you’ve got a log, it could be a fun morning.
After that, the final days fade out slowly—1.0m on the 18th and 19th, still with that long SSW period, but again small.
So overall, you’ve got a bit of a wait. The first real highlight is Monday the 7th morning for experts only—big, powerful, but tricky. The best all-round session is Wednesday the 16th. Don’t sleep on Thursday the 17th morning if you want clean little peelers on a longer board.
Keep your eyes on the forecasts, but right now, Number Fours is where it’s at.
Rusty
Short Range ForecastModerate rain (total 16mm), heaviest on Sun night. Warm (max 27°C on Sat afternoon, min 25°C on Fri night). Winds decreasing (strong winds from the ENE on Fri morning, light winds from the ENE by Sun night). | Days 4-6 Weather SummaryModerate rain (total 11mm), heaviest on Mon night. Warm (max 28°C on Mon afternoon, min 25°C on Wed night). Winds decreasing (fresh winds from the S on Mon night, light winds from the E by Tue night). | ||||||||||||||||||||
Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | |||||||||||||||
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) | S 12 | E 14 | E 14 | ENE 13 | ENE 13 | E 13 | ENE 12 | SSW 14 | SSW 14 | SW 15 | SW 14 | ENE 12 | ENE 11 | ENE 10 | SSW 14 | SSW 14 | E 13 | ENE 7 | ENE 7 | ENE 7 | ENE 8 |
Wave Graph | |||||||||||||||||||||
521 | 577 | 1977 | 1792 | 1616 | 1538 | 1240 | 1382 | 1960 | 4187 | 6058 | 1121 | 773 | 462 | 356 | 273 | 222 | 279 | 247 | 229 | 296 | |
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 | cross-on | on | on | on | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 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 | 3:05PM0.69m | 3:32AM0.45m | 3:39PM0.64m | 4:11AM0.50m | |||||||
Low Tide | 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 | 8:21AM0.06m | 9:46PM0.05m | 9:12AM0.07m | 10:10PM0.04m | ||||||||
6:15 | — | — | 6:15 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
— | 6:44 | — | — | 6:43 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | — | 6:38 | — | |
mm | — | — | — | — | — | — | — | 6 | 10 | 2 | — | 4 | 2 | 2 | 1 | — | — | — | — | — | — |
Temp °C | 26 | 26 | 25 | 26 | 27 | 26 | 27 | 26 | 26 | 27 | 28 | 27 | 27 | 27 | 27 | 27 | 27 | 26 | 26 | 26 | 26 |
Feels °C | 23 | 22 | 22 | 24 | 25 | 26 | 25 | 26 | 25 | 27 | 27 | 27 | 28 | 29 | 31 | 27 | 26 | 26 | 23 | 22 | 23 |
Swell 1 Height (m) Direction Period (s) | S 12 | E 14 | S 13 | S 12 | SSW 12 | SSW 12 | SSW 13 | ENE 12 | SSW 14 | SW 15 | SW 14 | WSW 11 | ENE 11 | ENE 10 | ENE 9 | SSW 14 | E 13 | E 13 | E 12 | E 13 | ENE 13 |
521 | 577 | 643 | 565 | 794 | 718 | 980 | 1338 | 1960 | 4187 | 6058 | 1027 | 773 | 462 | 216 | 273 | 222 | 212 | 196 | 229 | 282 | |
Swell 2 Height (m) Direction Period (s) | E 14 | S 11 | N 11 | SSW 17 | NNE 10 | NNE 9 | SW 16 | SSW 14 | S 18 | ENE 13 | ENE 13 | ENE 12 | SSW 9 | SSW 8 | SSW 14 | E 14 | SSW 13 | SSW 13 | SSW 13 | SSW 12 | SSW 16 |
357 | 244 | 10 | 112 | 19 | 15 | 129 | 1382 | 240 | 1844 | 1697 | 1121 | 371 | 232 | 356 | 232 | 204 | 133 | 131 | 89 | 175 | |
Swell 3 Height (m) Direction Period (s) | SW 12 | S 13 | SSW 20 | NNE 10 | S 22 | SSE 10 | SSW 20 | SSE 10 | N 9 | SSW 17 | SSW 16 | SSW 15 | W 10 | SSW 14 | SSW 8 | SSW 8 | SSW 7 | SSW 7 | SW 16 | SW 18 | SSW 12 |
6 | 280 | 38 | 20 | 9 | 19 | 76 | 19 | 7 | 367 | 694 | 505 | 320 | 371 | 83 | 44 | 30 | 16 | 133 | 155 | 47 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | E 14 | ENE 13 | ENE 13 | E 13 | ENE 12 | — | ENE 12 | — | — | S 10 | — | — | — | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 8 |
443 | 366 | 1977 | 1792 | 1616 | 1538 | 1240 | — | 1643 | — | — | 783 | — | — | — | 192 | 142 | 279 | 247 | 218 | 296 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 44 | 39 | 31 | 31 | 31 | 31 | 33 | 2 | 4 | 46 | 123 | 48 | 19 | 16 | 1 | 1 | 2 | 31 | 31 | 34 | 31 |
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.










