Surf Forecasts:
Number Fours surf forecast from 21 Aug 2026:
- Best quality surf: Saturday 22 Aug, 5AM (local time) - 2.5ft (0.8m), 16s period, SSW swell with cross-offshore winds.
- Most powerful swell: Thursday 27 Aug, 11AM (local time) - 3.5ft (1.0m), 17s period, S swell with 593 kJ wave energy.
- Next surfable swell (1★+): Friday 21 Aug, 5PM (local time) - 2.5ft (0.7m), 16s 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 Friday (Aug 21) at 5PM. The primary swell is predicted to be 0.7m and 16s 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 1.0m 17s and forecast to arrive on Thursday (Aug 27) at 11AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 6s period and expected on Monday (Aug 24) at 8AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5PM (Fri 21st Aug) | 2.5ft (0.7m) 16s |
| Best Surf | 5AM (Sat 22nd Aug) | 2.5ft (0.8m) 16s |
| Most Powerful | 11AM (Thu 27th Aug) | 3.5ft (1.0m) 17s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright folks, Rusty here with a look at what’s coming up for Number Fours. It’s a bit of a mixed bag over the next couple of weeks, so let’s get straight into it.
We’ve got a long stretch of strong, consistent trade winds blowing through, which is going to mess up the quality for paddle surfing for most of the first week and beyond. The opening is pretty grim, honestly. Friday the 21st has some small, clean surf with the swell around 2 ft from the SW, and a long 17-second period. The wind is light, making for some clean lines on the reef, but the wave energy is weak (291). It’s a marginal one at best.
Things then go sideways. From Saturday the 22nd right through to the end of the month, we’re looking at a persistent onslaught of strong cross-offshore winds, blowing 30 to 40 km/h (18 to 25 mph). The swell jumps up a bit, especially around the 23rd and 24th with some short-period, messy ENE windswell at 5 ft to 6 ft, but the wave energy is moderate to strong (422 to 575). The wind is ripping, making it pretty hopeless for a clean session.
There’s a glimmer of hope around the 26th and 27th. The wind eases slightly, but it’s still a fresh 30 km/h (18 mph) breeze. The swell drops back to 2 ft to 3 ft, but the direction swings to the S, and the period stretches out to 17 and 18 seconds – real groundswell. The combined energy is moderate to strong (647 to 831). Still, those winds are ruining the party. This period is better suited for a kite surfer than someone on a paddle board.
The real standout, and the one to circle on your calendar, is the end of the first week of September. This is for the experts out there. On Monday the 31st of August, into Tuesday the 1st of September, we see a serious pulse of swell. The swell height builds to 7 ft to 10 ft from the ENE with a 13-second period. The combined wave energy goes through the roof, hitting 1951 and then a massive 5515 on Tuesday. This is strong to very strong energy. For a reef break, that’s going to be powerful and take a good paddle. The catch? The wind is cranking 35 to 45 km/h (21 to 28 mph), and on Tuesday, it’s a near gale at 55 km/h (34 mph). This will be blown out and gnarly – a true big-wave, onshore challenge. It’s only for the top crew.
Looking further ahead, towards Saturday the 5th of September, we see a tease of something different. The wind drops to a moderate 20 km/h (12 mph), and the swell turns to a long-period 19-second groundswell from the SW at only 2 ft. The energy is moderate (663), and the very long period will make those sets fat and walled-up on the reef, but it might offer a clean, mellow wave if you’re patient.
Overall, the next 16 days have a lot of wind. Don’t hold your breath for the first week. The second week has more size and power, but it will be wild. If you’re paddling, the conditions are tough. If you’re kiting, it looks like a blast.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Fri afternoon, min 25°C on Thu night). Winds increasing (calm on Thu night, strong winds from the ENE by Sat night). | Days 5-7 Weather SummaryMostly dry. Warm (max 26°C on Mon morning, min 25°C on Sun night). Mainly fresh winds. | ||||||||||||||||||
Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | ||||||||||||||
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 16 | SW 17 | SW 16 | SSW 16 | SW 16 | SW 16 | E 7 | ENE 7 | ENE 7 | ENE 6 | SSW 14 | SSW 13 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | SSW 14 | S 18 | S 19 |
Wave Graph | |||||||||||||||||||
274 | 291 | 261 | 322 | 261 | 255 | 286 | 293 | 247 | 212 | 176 | 156 | 139 | 191 | 208 | 204 | 215 | 304 | 354 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | 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 | 10:11PM0.21m | 12:25PM0.59m | 00:08AM0.21m | 1:12PM0.63m | 1:06AM0.23m | 1:52PM0.66m | 1:46AM0.26m | 2:26PM0.67m | 2:21AM0.29m | 2:56PM0.68m | 2:55AM0.33m | 3:24PM0.68m | 3:31AM0.37m | ||||||
Low Tide | 8:27PM0.20m | 8:41PM0.17m | 5:06AM0.12m | 9:00PM0.16m | 6:08AM0.10m | 9:18PM0.14m | 6:59AM0.08m | 9:35PM0.13m | 7:43AM0.06m | 9:53PM0.11m | 8:24AM0.05m | 10:12PM0.10m | |||||||
— | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:13 | — | — | |
6:57 | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 26 | 27 | 27 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 25 | 25 |
Feels °C | 30 | 30 | 31 | 29 | 26 | 24 | 22 | 23 | 23 | 23 | 24 | 24 | 24 | 24 | 23 | 23 | 22 | 21 | 22 |
Swell 1 Height (m) Direction Period (s) | ENE 7 | SW 17 | NE 7 | SSW 16 | ENE 7 | SW 16 | SSW 16 | S 13 | SSW 15 | SW 14 | SSW 14 | SSW 13 | SSW 13 | SSW 12 | SSW 16 | SSW 15 | SSW 14 | S 18 | S 19 |
108 | 291 | 67 | 322 | 161 | 255 | 212 | 90 | 191 | 100 | 166 | 156 | 127 | 85 | 142 | 121 | 215 | 304 | 354 | |
Swell 2 Height (m) Direction Period (s) | SW 16 | NNE 7 | SW 16 | W 10 | SW 16 | W 10 | S 14 | SW 15 | SSE 13 | SSE 13 | SSE 12 | E 8 | SSE 12 | SSW 16 | SSW 12 | SSW 12 | S 18 | SSW 13 | SSW 13 |
274 | 42 | 261 | 50 | 261 | 53 | 104 | 116 | 34 | 96 | 50 | 36 | 78 | 146 | 81 | 81 | 165 | 135 | 137 | |
Swell 3 Height (m) Direction Period (s) | W 9 | W 11 | W 10 | S 13 | W 10 | S 12 | WNW 10 | SSW 15 | WNW 10 | SSW 15 | SSW 18 | SSE 12 | SSW 17 | SSE 12 | SSE 7 | SSW 18 | SSE 12 | SSE 12 | SSW 16 |
27 | 57 | 49 | 54 | 50 | 47 | 34 | 76 | 22 | 71 | 62 | 48 | 94 | 29 | 10 | 109 | 27 | 14 | 87 | |
Wind waves Height (m) Direction Period (s) | — | — | NE 7 | ENE 7 | NE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 6 | E 6 | ENE 7 |
— | — | 106 | 107 | 91 | 198 | 286 | 293 | 247 | 212 | 176 | 125 | 139 | 191 | 208 | 204 | 160 | 194 | 135 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 1 | 1 | 0 | 31 | 33 | 39 | 39 | 39 | 39 | 31 | 33 | 39 | 31 | 32 | 32 | 31 | 33 | 33 | 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.











