Surf Forecasts:
Number Fours surf forecast from 21 Aug 2026:
- Best quality surf: Thursday 20 Aug, 5PM (local time) - 2ft (0.6m), 17s period, SSW swell with cross-offshore winds.
- Most powerful swell: Thursday 27 Aug, 11AM (local time) - 3.5ft (1.1m), 17s period, S swell with 716 kJ wave energy.
- Next surfable swell (1★+): Thursday 20 Aug, 5PM (local time) - 2ft (0.6m), 17s 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 Thursday (Aug 20) at 5PM. The primary swell is predicted to be 0.6m and 17s period with a secondary swell of 1.1m and 7s. 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 1.1m 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 0.9m 7s period and expected on Friday (Aug 21) at 5PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5PM (Thu 20th Aug) | 2ft (0.6m) 17s |
| Best Surf | 5PM (Thu 20th Aug) | 2ft (0.6m) 17s |
| Most Powerful | 11AM (Thu 27th Aug) | 3.5ft (1.1m) 17s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
G’day, Rusty here. Alright, let’s have a look at what’s cooking at Number Fours for the next couple of weeks.
The first few days are a bit of a tease. We’ve got a nice little window on Thursday 20th and Friday 21st August, with some clean, glassy conditions and a small but long-period groundswell. After that, the wind really starts to howl and things go a bit ragged for a solid week. There’s a long stretch of poor to marginal conditions from Saturday 22nd through to Wednesday 2nd September. Then, just when you’re about to give up, the forecast hints at a proper little gem right at the end of the run, on Friday 4th September.
Thursday 20th August (Morning & Afternoon): This is where we start. The swell is small, coming in at 2ft from the SSW, but it’s got a very long period of 18 seconds. That’s proper groundswell energy, and with combined swell energy at 261 (weak), it’s not going to be pumping, but it will have shape. The wind is light cross-off at 3-6 mph, and the water temp is a comfortable 80°, bang on average for this time of year. It’s clean, it’s small, but it’s surfable.
Friday 21st August (Morning & Afternoon): Swell bumps up just a touch to 2ft from the SW, still with a long period of 16-17 seconds. The morning is a bit messy with a cross-shore breeze, but the afternoon turns glassy. Combined energy is still low at 264 (weak), but with zero wind in the arvo, you’ll be getting some clean little lines. It’s a good day to be out if you’ve got a log or a fish.
Saturday 22nd August – Monday 1st September: A long, ugly stretch. The wind cranks up to 22-28 mph from the ENE, which is cross-off but way too strong for clean surfing. Swell bounces between 2ft and 7ft, but with that brutal wind, the surface will be a mess. On the 23rd and 24th, the period drops to a short 6-7 seconds, so it’s choppy and weak. Combined energy gets up into the 500-800 range (moderate) but the quality is just poor. This is more of a kite-surfing setup than a paddle session. From the 26th onwards, things shift to marginal with a bit more south in the swell, but the wind is relentless. It’s a write-off.
Thursday 3rd September (Morning): The wind finally starts to ease. Swell is a solid 7ft from the ENE with a period of 9 seconds, and combined energy is a strong 1397. This is expert-only territory, as anything over 8ft gets serious. The wind is down to 9 mph, which makes it cleaner, but the size and power are going to be challenging. It’s a step in the right direction.
Friday 4th September (Morning & Afternoon): This is the standout. The wind drops right off to 3-6 mph from the NE, going glassy in the afternoon. Swell sits at a very manageable 5-6ft from the ENE, with a period of 9 seconds. Combined energy is moderate at 520-607, but the quality is where it’s at. With light winds and clean conditions, this is the pick of the forecast. It’s a bit far out, so don’t bank on it, but if it holds, Friday 4th September will be the day to be at Number Fours. Just keep an eye on the crowds, as this spot can get busy.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Thu afternoon, min 25°C on Thu morning). Winds increasing (calm on Thu night, strong winds from the ENE by Sat night). | Days 4-6 Weather SummaryMostly dry. Warm (max 26°C on Sun morning, min 25°C on Sun morning). Mainly strong winds. | ||||||||||||||||||||
Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | |||||||||||||||
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) | SSW 18 | SSW 17 | SW 16 | SW 17 | SW 16 | SSW 16 | SW 16 | SW 16 | E 7 | ENE 7 | ENE 7 | ENE 7 | SSW 14 | SSW 13 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | SSW 14 | S 19 | S 18 |
Wave Graph | |||||||||||||||||||||
207 | 200 | 274 | 291 | 264 | 322 | 261 | 255 | 255 | 220 | 295 | 247 | 188 | 156 | 181 | 254 | 284 | 212 | 215 | 450 | 311 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross | 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 |
High Tide | 11:25AM0.56m | 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 | — | — | 6:11 | — | — | 6:13 | — | — | |
— | 6:57 | — | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 27 | 26 | 26 | 27 | 27 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 25 | 25 |
Feels °C | 29 | 30 | 29 | 29 | 30 | 30 | 27 | 23 | 23 | 23 | 23 | 22 | 24 | 24 | 23 | 24 | 25 | 24 | 24 | 23 | 23 |
Swell 1 Height (m) Direction Period (s) | E 8 | ENE 7 | ENE 7 | NE 7 | NE 7 | SSW 16 | SW 16 | SW 16 | SSW 16 | E 8 | SSW 15 | SW 14 | SSW 14 | SSW 13 | SSW 13 | SSW 12 | SSW 16 | SSW 15 | SSW 14 | S 19 | S 18 |
54 | 131 | 108 | 57 | 67 | 322 | 261 | 255 | 212 | 64 | 191 | 100 | 166 | 156 | 127 | 85 | 142 | 121 | 215 | 450 | 311 | |
Swell 2 Height (m) Direction Period (s) | NE 6 | SSW 17 | SW 16 | SW 17 | SW 16 | W 10 | WNW 10 | W 11 | S 14 | SW 15 | WNW 12 | SSE 13 | SSE 12 | ESE 8 | E 8 | SSW 16 | SSW 12 | SSW 12 | SSW 18 | SSW 13 | SSW 13 |
42 | 200 | 274 | 291 | 264 | 50 | 35 | 58 | 106 | 115 | 27 | 56 | 85 | 55 | 37 | 146 | 56 | 56 | 107 | 135 | 135 | |
Swell 3 Height (m) Direction Period (s) | SSW 18 | W 11 | W 9 | W 11 | W 10 | S 13 | S 12 | S 12 | WNW 10 | S 13 | SSE 13 | SSW 15 | SSW 18 | SSE 12 | SSW 17 | SSE 12 | SSE 7 | SSW 18 | S 21 | SSE 12 | SSW 16 |
207 | 37 | 27 | 57 | 49 | 54 | 47 | 47 | 35 | 90 | 35 | 71 | 62 | 47 | 94 | 28 | 9 | 109 | 79 | 27 | 51 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | ENE 7 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 6 | ENE 6 | ENE 6 |
— | — | — | — | — | 85 | 117 | 178 | 255 | 220 | 295 | 247 | 188 | 113 | 181 | 254 | 284 | 212 | 172 | 161 | 147 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 0 | 0 | 1 | 0 | 0 | 31 | 42 | 39 | 46 | 48 | 31 | 33 | 39 | 31 | 32 | 33 | 31 | 31 | 31 | 4 |
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.











