
Surf Forecasts:
Number Fours surf forecast from 13 Sep 2026:
- Best quality surf: Monday 14 Sep, 5AM (local time) - 1.5ft (0.5m), 14s period, SW swell with cross-offshore winds.
- Most powerful swell: Friday 18 Sep, 2AM (local time) - 7.5ft (2.3m), 9s period, ENE swell with 772 kJ wave energy.
- Next surfable swell (1★+): Monday 14 Sep, 5AM (local time) - 1.5ft (0.5m), 14s period with SW 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 14) at 5AM. The primary swell is predicted to be 0.5m 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 2.3m 9s and forecast to arrive on Friday (Sep 18) at 2AM. 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 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Mon 14th Sep) | 1.5ft (0.5m) 14s |
| Best Surf | 5AM (Mon 14th Sep) | 1.5ft (0.5m) 14s |
| Most Powerful | 2AM (Fri 18th Sep) | 7.5ft (2.3m) 9s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s talk about Number Fours. The next week and a half? Pretty quiet. Don’t rush to the water. We’ve got a long stretch of small, weak surf before things finally show some life in the second half of the month.
Right now, the water’s a warm 81°, which is about average for this time of year. Nothing out of the ordinary.
From Sunday the 13th through at least Wednesday the 16th, we’re looking at tiny surf – 0.3m to 0.9m – with a long period from the SW. That long period is good for shape, but there’s just no push. The wind is cross-off from the ENE and NE, so the surface is clean, but the combined swell energy is low to moderate (133 to 682). The wave reports say it’s poor or marginal. Honestly, it’s a no-go. You’d be wasting your time.
Thursday the 17th brings a jump to 2.2m, but it’s short-period windswell from the ENE (7 seconds) and the combined energy climbs to 941. This is messy, choppy, and not what you want on a reef. The wind is cross-off but strong, around 35 km/h. It’s not clean, and for Number Fours, that’s a pass.
Friday the 18th is a bit better with 1.0m of SSW swell at a 17-second period. The combined energy is high (over 1000), and the wind is still cross-off. The wave comment says it’s marginal, but the quality is there. It’s not a standout – just a metre of swell – but it’s the best we’ve seen so far.
From Saturday the 19th through the end of the month, it’s a mixed bag. Swell heights range from 1.5m to 2.4m, mostly from the ENE and E, with short to moderate periods (7 to 13 seconds). The combined energy gets strong, especially on Tuesday the 22nd afternoon (1497) and Wednesday the 23rd (1441). The wind stays cross-off, keeping the surface clean, but the swell direction isn’t lining up with the optimum for Number Fours, which wants a SSE direction.
The best window is around Tuesday the 22nd afternoon and Wednesday the 23rd. We’ve got 1.9m to 2.4m of ENE swell with the period bumping up to 11-13 seconds, and strong combined energy (1497 and 1441). The wind is cross-off from the ENE. This will produce clean, punchy waves, but the direction is off, so it won’t be the classic Number Fours shape. Still, for the size and energy, this is the best on offer across the whole 16 days.
After that, it fades into the final week with similar, less exciting conditions. The swell drops back to 0.9m on the 28th, with a nice long period from the SSW (17 seconds) and strong energy (942). That could be a fun, clean session on a longboard, but it’s not a standout.
Overall, this is a long period of waiting. The first week is a write-off. The second week has some size and energy, but the direction is never quite right. If you’re a local, you might get a few fun waves on the 22nd or 23rd, but don’t expect perfection. The crowds at Number Fours can sometimes be an issue, but with this forecast, I wouldn’t worry – it won’t be packed.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Tue afternoon, min 24°C on Sun night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 8mm), mostly falling on Thu night. Warm (max 27°C on Wed morning, min 26°C on Wed morning). Mainly fresh winds. | ||||||||||||||||||||
Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | |||||||||||||||
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 15 | SSW 15 | SW 12 | SW 23 | SW 22 | SW 21 | SW 20 | SW 19 | SSW 19 | SW 18 | SSW 18 | SSW 17 | ENE 7 | ENE 9 | ENE 9 | ENE 8 | SSW 17 | SSW 16 | ENE 8 | SSW 16 | ENE 8 |
Wave Graph | |||||||||||||||||||||
107 | 84 | 38 | 86 | 227 | 224 | 392 | 384 | 470 | 455 | 541 | 377 | 516 | 711 | 772 | 622 | 580 | 539 | 416 | 416 | 473 | |
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 | 5:11PM0.43m | 6:14AM0.58m | 5:40PM0.36m | 7:02AM0.58m | 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 | ||||||||
Low Tide | 11:45AM0.17m | 11:19PM0.06m | 12:45PM0.20m | 11:42PM0.08m | 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 | |||||||
6:16 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
— | 6:36 | — | — | 6:35 | — | — | 6:34 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 7 | 1 | — | — | — | — | — |
Temp °C | 26 | 26 | 25 | 26 | 26 | 26 | 26 | 27 | 26 | 27 | 27 | 26 | 26 | 27 | 26 | 27 | 27 | 26 | 26 | 26 | 26 |
Feels °C | 26 | 26 | 25 | 25 | 25 | 26 | 27 | 27 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 24 | 24 | 24 | 25 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | NNE 9 | NNE 9 | NE 9 | NE 8 | SW 22 | NNE 8 | SW 20 | SW 19 | SSW 19 | SW 18 | SSW 18 | SSW 17 | SW 16 | SW 16 | SSW 18 | SSW 17 | ENE 8 | SSW 16 | SSW 16 | SSW 16 | S 16 |
99 | 99 | 79 | 74 | 227 | 44 | 392 | 384 | 470 | 455 | 541 | 377 | 258 | 258 | 644 | 622 | 473 | 539 | 306 | 387 | 257 | |
Swell 2 Height (m) Direction Period (s) | SW 15 | SSW 15 | SW 12 | SW 14 | SW 14 | SW 21 | NNE 8 | E 12 | E 11 | E 10 | E 10 | E 10 | SSW 20 | SSW 19 | SSE 10 | SSE 10 | SSW 17 | SSE 8 | SSE 8 | SSE 7 | SSW 13 |
107 | 84 | 38 | 49 | 49 | 224 | 25 | 68 | 58 | 73 | 98 | 100 | 149 | 210 | 9 | 9 | 580 | 44 | 38 | 31 | 102 | |
Swell 3 Height (m) Direction Period (s) | ENE 9 | SW 12 | ENE 8 | SW 23 | SSW 11 | SSW 13 | E 12 | SW 12 | NNE 8 | SW 12 | SW 11 | SSW 11 | SW 11 | SW 10 | WSW 10 | W 9 | SSE 8 | S 20 | SSW 18 | SSW 18 | SW 16 |
26 | 37 | 14 | 86 | 12 | 68 | 46 | 38 | 22 | 35 | 43 | 12 | 18 | 4 | 9 | 2 | 27 | 67 | 106 | 106 | 122 | |
Wind waves Height (m) Direction Period (s) | E 4 | ENE 9 | ENE 4 | ENE 5 | NE 8 | ENE 5 | ENE 5 | NE 8 | ENE 5 | ENE 6 | NE 6 | ENE 6 | ENE 7 | ENE 9 | ENE 9 | ENE 8 | — | ENE 8 | ENE 8 | ENE 8 | ENE 8 |
9 | 59 | 13 | 19 | 149 | 27 | 32 | 116 | 66 | 101 | 133 | 265 | 516 | 711 | 772 | 585 | — | 416 | 416 | 416 | 473 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 1 | 2 | 31 | 1 | 1 | 1 | 2 | 1 | 31 | 126 | 31 | 126 | 42 | 33 | 39 | 42 | 31 | 39 | 33 | 33 |
Best forecast wave conditions in Oahu | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
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.










