Surf Forecasts:
Number Fours surf forecast from 22 Aug 2026:
- Best quality surf: Saturday 22 Aug, 2AM (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 587 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 Wednesday (Aug 26) at 11PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5PM (Fri 21st Aug) | 2.5ft (0.7m) 16s |
| Best Surf | 2AM (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, looking at the next stretch for Number Fours. It’s a mixed bag, so let's get into it.
We’re kicking off Friday the 21st of August with some real small, clean conditions. The water’s sitting at a normal 81° for this time of year, so no surprises there. That morning has a light cross-onshore breeze, nothing to write home about, but by Friday afternoon the wind swings cross-offshore and it’s glassy. That afternoon session is our first real standout. You’ve got a little 2ft groundswell from the south-west, but get this – it’s packing a 16-17 second period. That’s proper long-period energy, which will make this tricky reef break (Number Fours) really stand up and offer some nice, lined-up waves. The combined energy is low though, only (342), so it’s not a beast, but it’ll be clean and fun.
Now, don’t get too excited for the next few days. Saturday the 22nd through Monday the 25th are pretty much a write-off. We get hit by a fresh to strong breeze from the ENE, blowing 22-25 mph. The swell is tiny at 2ft and messy, or it’s short-period junk. The combined energy climbs into the moderate range, hitting (527) and even (618), but the wind is just going to ruin it. This is a stretch of bleakness for paddling.
We finally see a glimmer on Wednesday the 26th. The wind is still fresh, but the swell starts shifting more southerly. By Thursday the 27th morning, we get a solid push of south swell at 4ft with a 17-second period, and the combined energy jumps right up to (1012). That’s moderate-to-strong energy hitting the reef. The wind is still cross-off, so it’ll be clean, but it’s still a bit breezy. This one is promising, but not a total gem.
Then, we hit a massive wait. From the 28th through the 30th, it's all marginal with onshore winds and weak, short-period easterly slop. The combined energy hangs around the 700-900 range, but the quality just isn't there for good paddling.
Hold on, because the end of the period makes it all worth it. Monday the 31st of August and Tuesday the 1st of September see a proper swell event. The swell jumps to a solid 10ft to 12ft from the ENE, with the combined energy blasting through the roof at (2133) and even (2882). That is strong to very strong wave energy. However, there’s a huge caveat here. For Monday the 31st, it’s an 11-second period, dropping to 10 seconds, which is moderate. At 10ft+, this is big, powerful, and for experts only at this reef. On top of that, the wind is howling from the NE at 19-31 mph. Monday afternoon is still cross-off, but Tuesday the 1st gets a near gale. For most of us, this will be a washed-out, dangerous mess. It’s more interesting for kite surfing than paddle surfing through that wind.
We get a slight cleanup into Wednesday the 2nd and Thursday the 3rd, with the swell dropping to a still-sizeable 6-7ft. The period drops off to a short, punchy 8-9 seconds, and the wind eases. There’s a potential for decent, racy waves on the later afternoons if the wind holds cross-off. The combined energy is still moderate, around (700-900). The standout of that little run is Friday the 4th of September afternoon. Swell is 5ft from the ENE at 8 seconds, but the wind is light and cross-off, and the score bumps up. It’s the first truly “very good” conditioned call in a long time.
The last call is Saturday the 5th of September with a bit more period at 12 seconds and a mellow 5ft, but with that light cross-off wind it has potential for a clean finish.
So, if you had to pick. The true standout is that first Friday afternoon, the 21st. It’s small but glassy on a long-period groundswell. The second standout is the far-off Saturday, the 5th of September, with a longer-period swell and light wind – it’s promising, but don’t book your flights yet.
Stay safe, check the tides, and I’ll see you out there.
Rusty
Short Range ForecastSome drizzle, heaviest during Mon morning. Warm (max 27°C on Fri afternoon, min 25°C on Sat night). Winds increasing (light winds from the E on Fri afternoon, strong winds from the ENE by Sun afternoon). | Days 5-7 Weather SummaryMostly dry. Warm (max 27°C on Mon afternoon, min 25°C on Tue night). Mainly fresh winds. | |||||||||||||||||||
Fri 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | ||||||||||||||
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 16 | SSW 16 | SW 16 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 7 | SSW 14 | S 18 | S 19 | S 17 | S 16 | S 16 |
Wave Graph | ||||||||||||||||||||
261 | 322 | 261 | 270 | 423 | 302 | 286 | 317 | 268 | 247 | 247 | 327 | 293 | 225 | 215 | 307 | 351 | 587 | 427 | 482 | |
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 |
High Tide | 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 | 3:53PM0.66m | 4:08AM0.41m | |||||||
Low Tide | 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 | 9:05AM0.06m | 10:32PM0.08m | |||||||
— | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | |
6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | — | 6:52 | — | |
mm | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 27 | 26 | 26 | 26 | 26 | 26 | 25 | 26 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 30 | 29 | 25 | 24 | 24 | 22 | 22 | 22 | 24 | 25 | 25 | 25 | 23 | 23 | 23 | 23 | 23 | 24 | 24 | 22 |
Swell 1 Height (m) Direction Period (s) | NE 7 | SSW 16 | SW 16 | SW 16 | SSW 16 | SSE 13 | SSW 15 | SW 14 | SSW 14 | SSW 13 | SSW 13 | SSW 12 | SSW 16 | SSW 15 | SSW 14 | S 18 | S 19 | S 17 | S 16 | S 16 |
67 | 322 | 261 | 255 | 212 | 101 | 191 | 100 | 168 | 156 | 127 | 85 | 142 | 121 | 215 | 307 | 351 | 587 | 427 | 482 | |
Swell 2 Height (m) Direction Period (s) | SW 16 | W 10 | W 10 | W 10 | S 14 | SW 15 | SSE 13 | SSE 13 | SSE 12 | SSE 12 | SSE 12 | SSW 16 | SSW 12 | SSW 12 | S 18 | SSW 13 | SSW 13 | SSW 12 | SSW 12 | E 18 |
261 | 50 | 50 | 53 | 104 | 116 | 67 | 56 | 50 | 48 | 46 | 146 | 81 | 81 | 165 | 135 | 137 | 79 | 55 | 154 | |
Swell 3 Height (m) Direction Period (s) | W 10 | S 13 | S 12 | S 12 | WNW 10 | SSW 15 | WNW 10 | SSW 15 | SSW 18 | SSE 8 | SSW 17 | SSE 7 | SSE 6 | SSW 18 | SSE 6 | SSE 12 | SSW 16 | N 8 | N 8 | N 8 |
49 | 54 | 47 | 47 | 34 | 76 | 20 | 71 | 62 | 12 | 94 | 20 | 8 | 109 | 4 | 14 | 50 | 6 | 5 | 4 | |
Wind waves Height (m) Direction Period (s) | NE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 6 |
106 | 144 | 173 | 270 | 423 | 302 | 286 | 317 | 268 | 247 | 247 | 327 | 293 | 225 | 194 | 139 | 155 | 98 | 111 | 119 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 0 | 0 | 39 | 39 | 39 | 42 | 126 | 39 | 39 | 39 | 31 | 33 | 39 | 31 | 33 | 33 | 31 | 31 | 44 | 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.











