
Surf Forecasts:
Number Fours surf forecast from 3 Sep 2026:
- Best quality surf: Monday 7 Sep, 8PM (local time) - 21ft (6.5m), 14s period, SSW swell with cross-onshore winds.
- Most powerful swell: Monday 7 Sep, 8PM (local time) - 21ft (6.5m), 14s period, SSW swell with 16,463 kJ wave energy.
- Next surfable swell (1★+): Monday 7 Sep, 8PM (local time) - 21ft (6.5m), 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 Monday (Sep 07) at 8PM. The primary swell is predicted to be 6.5m and 14s period with a secondary swell of 2.2m and 12s. The wind is predicted to be cross-onshore as the swell arrives.
The most powerful waves expected at Number Fours in the next 16 days are 6.5m 14s and forecast to arrive on Monday (Sep 07) at 8PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.2m 10s period and expected on Tuesday (Sep 08) at 5AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8PM (Mon 7th Sep) | 21ft (6.5m) 14s |
| Best Surf | 8PM (Mon 7th Sep) | 21ft (6.5m) 14s |
| Most Powerful | 8PM (Mon 7th Sep) | 21ft (6.5m) 14s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, let’s get into it. This is Rusty, and I’m looking at the next couple of weeks for Number Fours.
Right off the bat, we’ve got a bit of a wait. The first few days are pretty grim—strong cross-off winds in the 25 mph range are messing up a building swell, leaving the surf in poor shape. It’s not until the end of the first week that things start to get interesting.
The standout session looks to be Monday, September 7th. The swell jumps to a solid 15 ft out of the SSW, with a very long period of 15 seconds. The wave energy is off the charts (11848), which is just huge. The wind is a clean cross-shore, making it rideable for the experienced crew. But let’s be real, at 15 ft, this is not one for the beginners—this is expert territory only. That kind of long-period groundswell will be breaking a bit straight at a reef, but the power will be there in spades. This is the one to circle on the calendar, but keep in mind, it’s a week out, so keep an eye on the forecasts.
The run-up to that is worth a mention too. Saturday, September 5th, through Sunday, September 6th, has consistent 7 ft to 8 ft ENE swell with moderate to fresh cross-off breezes and decent energy (up to 2733). It’s a reliable couple of days for intermediate surfers, with clean conditions and plenty of push.
Then, after that big Monday, the surf drops off quickly. Tuesday, September 8th, is back to poor conditions. But then, we get a beautiful little window on Wednesday, September 9th. The swell is small, around 3 ft, but it’s glassy in the morning—ESE wind at just 3 mph. The water temp is about average for this time of year, so no surprises there. It’ll be small and clean, perfect for a longboard or a fun fish.
After that, the second week looks pretty monotonous. There’s a persistent ENE swell running from 3 ft up to 7 ft through the end of the week, but it’s all marred by moderate to fresh cross-off winds. It’s a bit of a rinse-and-repeat situation. Keep your expectations in check.
Then, as we push into the second weekend, we get another big pulse. Monday, September 14th to Tuesday, September 15th, the swell builds to 16 ft with strong energy (up to 6678). This could be a monster, but confidence is lower this far out. If it holds, it’s another day for experts only, and the crowds will be likely at a spot that sometimes gets busy.
Overall, the best bet is that Monday the 7th. The rest of the run is patchy, with the early part blown out and the back half a mix of manageable but not epic. For the reliable, everyday surfer, the weekend of the 5th and the glassy morning of the 9th are your best bets for a fun, clean session.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Sat afternoon, min 25°C on Thu morning). Mainly strong winds. | Days 4-6 Weather SummaryHeavy rain (total 35mm), heaviest during Sun afternoon. Warm (max 28°C on Tue afternoon, min 24°C on Sun night). Winds decreasing (near gales from the SSE on Mon night, calm by Tue night). | ||||||||||||||||||||
Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | |||||||||||||||
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 7 | ENE 7 | ENE 7 | ENE 7 | E 14 | E 14 | ENE 13 | ENE 13 | ENE 13 | ENE 12 | ENE 12 | SSW 14 | SSW 15 | SSW 15 | SSW 10 | S 9 | SSW 15 | SSW 14 | SSW 14 | E 14 | E 13 |
Wave Graph | |||||||||||||||||||||
512 | 512 | 443 | 498 | 577 | 775 | 1831 | 1616 | 1750 | 1568 | 1535 | 2277 | 4096 | 10643 | 2210 | 641 | 376 | 289 | 273 | 232 | 225 | |
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 | cross-off | cross | cross-on | on | on | on | glassy | cross-off | cross-off | cross-off |
High Tide | 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 | 3:05PM0.69m | 3:32AM0.45m | |||||||
Low Tide | 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 | 8:21AM0.06m | 9:46PM0.05m | ||||||||
6:15 | — | — | 6:15 | — | — | 6:15 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
— | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | |
mm | — | — | — | — | — | — | — | — | — | 2 | 7 | 10 | 2 | 2 | 10 | 2 | — | — | 2 | 1 | — |
Temp °C | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 27 | 26 | 27 | 27 | 25 | 26 | 27 | 27 | 27 | 28 | 27 | 27 | 27 | 26 |
Feels °C | 23 | 22 | 21 | 22 | 22 | 21 | 24 | 25 | 26 | 27 | 26 | 23 | 24 | 26 | 23 | 27 | 31 | 32 | 31 | 27 | 25 |
Swell 1 Height (m) Direction Period (s) | S 15 | SSE 12 | S 13 | S 12 | E 14 | E 14 | S 12 | S 12 | SSW 12 | SSW 12 | SSW 13 | SSW 14 | SSW 15 | SSW 15 | WSW 11 | S 9 | S 9 | SSW 9 | ENE 8 | ENE 7 | E 13 |
209 | 226 | 345 | 423 | 577 | 775 | 469 | 547 | 579 | 1003 | 1306 | 2277 | 4096 | 10643 | 1164 | 641 | 325 | 158 | 142 | 147 | 225 | |
Swell 2 Height (m) Direction Period (s) | E 13 | S 14 | E 14 | E 14 | S 12 | S 12 | SW 18 | SSW 18 | SSW 16 | SSE 10 | SSE 10 | N 9 | NW 15 | ENE 13 | ENE 12 | ENE 11 | ENE 10 | ENE 8 | SSW 8 | SSW 13 | SSW 13 |
162 | 200 | 334 | 357 | 423 | 400 | 78 | 120 | 288 | 19 | 18 | 7 | 8 | 1946 | 950 | 460 | 258 | 173 | 90 | 204 | 176 | |
Swell 3 Height (m) Direction Period (s) | SSE 12 | E 12 | SW 18 | SW 18 | SW 13 | N 11 | NNE 10 | NNE 10 | SSE 9 | SSE 10 | N 10 | N 9 | — | — | SSW 15 | W 8 | SSW 15 | SSW 14 | SSW 14 | E 14 | SSW 8 |
94 | 145 | 12 | 12 | 27 | 10 | 20 | 19 | 9 | 19 | 8 | 7 | — | — | 402 | 163 | 376 | 289 | 273 | 232 | 34 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 13 | ENE 13 | ENE 13 | ENE 12 | ENE 12 | ENE 12 | ENE 13 | SSE 7 | SSW 10 | — | — | — | — | — | ENE 7 |
512 | 512 | 443 | 498 | 456 | 346 | 1831 | 1616 | 1750 | 1568 | 1535 | 1649 | 2090 | 703 | 2210 | — | — | — | — | — | 199 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 44 | 128 | 46 | 39 | 46 | 127 | 39 | 33 | 33 | 31 | 31 | 32 | 1 | 127 | 123 | 147 | 26 | 16 | 0 | 0 | 0 |
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.










