
Surf Forecasts:
Number Fours surf forecast from 17 Jul 2026:
- Most powerful swell: Thursday 23 Jul, 11PM (local time) - 3ft (0.9m), 19s period, SSW swell with 560 kJ wave energy.
Best Forecast Surf Conditions for Number Fours this week:
The most powerful waves expected at Number Fours in the next 16 days are 0.9m 19s and forecast to arrive on Thursday (Jul 23) at 11PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 7s period and expected on Saturday (Jul 18) at 2AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11PM (Thu 23rd Jul) | 3ft (0.9m) 19s |
Table - best surf conditions forecast for Number Fours over the next 16 days.
The Lowdown
Alright, folks, Rusty here. Let’s break down Number Fours for the next couple of weeks.
First week is a bit of a grind. The wind is blowing hard from the ENE, cross-off, and the swell is a mess of short-period wind and long-period stuff that just doesn’t line up. Water temp is about average for the time of year. From Friday the 17th through Sunday the 20th, it’s a total write-off – scores are zero, and the energy is weak to moderate (329 to 551). Not worth getting wet.
Monday the 21st and Tuesday the 22nd are a little better, but still marginal. Swell is tiny, around 3 ft to 3 ft, with a long period from the S (14 to 16 seconds), but the wind is still cross-off at 15 to 19 mph. Energy is moderate (506 to 571), but the waves are just not there.
Mid-week, Wednesday the 23rd and Thursday the 24th see bigger energy numbers – 752 to 1160 – but the swell height is still small to moderate (2 ft to 5 ft). The real standout is the long-period groundswell from the SSW on Wednesday (24 seconds!), but it’s breaking straight at this reef, so it won’t be the classic shape. Thursday the 24th brings a more consistent 5 ft from the ENE with a 12-second period – that’s the best of the first week, but still marginal.
Second week picks up strong. From Friday the 25th through to Wednesday the 31st, we get a solid run of bigger, more powerful swells. The combined energy climbs into the four-digit range (741 to 2444). The swell height builds from 2 ft to 8 ft, with the biggest and best being on Tuesday the 29th afternoon and Wednesday the 30th morning. On Tuesday the 29th afternoon, we’ve got 8 ft from the ENE with a 14-second period – that’s expert territory, and the energy is a massive 2444. Wednesday the 30th morning is 7 ft from the ENE at 13 seconds, still strong. The wind stays cross-off from the ENE, which is clean but not glassy. For genuine experts, that window from Tuesday the 29th afternoon to Thursday the 31st morning is the true standout. The sets will be long and powerful, but it’s a reef, so you’ll need to know your line.
After that, it drops off hard. Friday the 1st and Saturday the 2nd of August are back to poor conditions with tiny wind swell.
Overall, the best bet is the late July window – from the 29th to the 31st – for the big, clean, powerful groundswell. It’s not for beginners, but if you’ve got the skills, that’s the time to go. Crowds are possible, but with that size, it’ll thin out the pack.
Rusty.
Short Range ForecastMostly dry. Warm (max 26°C on Fri morning, min 24°C on Sat night). Mainly strong winds. | Days 5-7 Weather SummaryMostly dry. Warm (max 26°C on Mon afternoon, min 24°C on Sun night). Mainly fresh winds. | ||||||||||||||||||
Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | ||||||||||||||
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 14 | SW 16 | SSW 16 | ENE 7 | E 7 | ENE 7 | ENE 8 | E 7 | ENE 8 | ENE 8 | ENE 8 | S 16 | S 15 | S 14 | S 14 | S 13 | SSW 24 | SSW 23 | ENE 12 |
Wave Graph | |||||||||||||||||||
211 | 149 | 196 | 214 | 400 | 337 | 353 | 247 | 232 | 232 | 191 | 321 | 339 | 329 | 298 | 273 | 317 | 426 | 531 | |
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 |
High Tide | 6:41AM0.30m | 6:36PM0.61m | 7:44AM0.34m | 7:11PM0.52m | 8:53AM0.38m | 7:45PM0.43m | 10:04AM0.43m | 8:19PM0.34m | 11:13AM0.49m | 8:56PM0.27m | 12:12PM0.54m | 10:06PM0.22m | |||||||
Low Tide | 1:08AM0.01m | 11:44AM0.08m | 1:42AM0.01m | 12:46PM0.16m | 2:15AM0.02m | 2:03PM0.22m | 2:48AM0.03m | 3:52PM0.27m | 3:23AM0.04m | 6:20PM0.26m | 4:02AM0.05m | 8:25PM0.21m | |||||||
— | 5:58 | — | — | 5:58 | — | — | 5:58 | — | — | 6:00 | — | — | 6:00 | — | — | 6:00 | — | — | |
7:15 | — | 7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:14 | — | — | 7:14 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 25 | 26 | 26 | 25 | 26 | 25 | 25 | 25 | 26 | 25 | 25 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 24 | 25 | 24 | 24 | 22 | 21 | 23 | 22 | 24 | 23 | 24 | 24 | 24 | 25 | 24 | 24 | 24 | 24 | 23 |
Swell 1 Height (m) Direction Period (s) | NE 7 | W 14 | SSW 16 | NE 7 | SSW 13 | SSW 14 | SSW 14 | S 12 | SSW 13 | SSW 12 | S 14 | S 16 | S 15 | S 14 | S 14 | S 13 | S 13 | SSW 23 | S 13 |
75 | 144 | 196 | 99 | 141 | 158 | 156 | 73 | 95 | 44 | 142 | 321 | 339 | 329 | 298 | 273 | 126 | 426 | 157 | |
Swell 2 Height (m) Direction Period (s) | SW 14 | SW 16 | W 14 | E 6 | WNW 13 | WNW 13 | W 12 | S 19 | S 18 | S 18 | S 16 | SW 18 | SW 16 | SW 17 | SW 16 | E 14 | S 11 | S 13 | SSW 22 |
211 | 125 | 98 | 62 | 57 | 56 | 28 | 66 | 106 | 97 | 135 | 81 | 69 | 72 | 68 | 64 | 82 | 125 | 363 | |
Swell 3 Height (m) Direction Period (s) | W 14 | SSW 12 | SSW 12 | SSW 14 | SW 15 | SSE 9 | SSE 6 | NNE 8 | NE 8 | NE 8 | SW 18 | W 12 | E 12 | E 12 | E 11 | SW 15 | SSW 24 | S 10 | SSW 17 |
148 | 55 | 55 | 147 | 55 | 8 | 4 | 11 | 15 | 16 | 83 | 11 | 12 | 25 | 23 | 60 | 317 | 80 | 202 | |
Wind waves Height (m) Direction Period (s) | E 6 | ENE 6 | ENE 7 | ENE 7 | E 7 | ENE 7 | ENE 8 | E 7 | ENE 8 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 12 | ENE 7 | ENE 12 |
59 | 149 | 134 | 214 | 400 | 337 | 353 | 247 | 232 | 232 | 191 | 169 | 144 | 117 | 117 | 129 | 266 | 121 | 531 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 31 | 31 | 39 | 1 | 39 | 39 | 4 | 31 | 31 | 1 | 2 | 31 | 1 | 1 | 31 | 31 | 31 | 32 | 2 |
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.










