Surf Forecasts:
Big Rock surf forecast from 15 Aug 2026:
- Best quality surf: Monday 17 Aug, 2PM (local time) - 16ft (5.0m), 17s period, WSW swell with onshore winds.
- Most powerful swell: Monday 17 Aug, 2PM (local time) - 16ft (5.0m), 17s period, WSW swell with 13,783 kJ wave energy.
- Next surfable swell (1★+): Sunday 16 Aug, 2AM (local time) - 7ft (2.2m), 13s period with WSW swell.
Best Forecast Surf Conditions for Big Rock this week:
The surf forecast for Big Rock over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Aug 16) at 2AM. The primary swell is predicted to be 2.2m and 13s period with a secondary swell of 1.3m and 16s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Big Rock in the next 16 days are 5.0m 17s and forecast to arrive on Monday (Aug 17) at 2PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.2m 6s period and expected on Monday (Aug 17) at 8AM.
| Wave Type | Time (AWST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Sun 16th Aug) | 7ft (2.2m) 13s |
| Best Surf | 2PM (Mon 17th Aug) | 16ft (5.0m) 17s |
| Most Powerful | 2PM (Mon 17th Aug) | 16ft (5.0m) 17s |
Table - best surf conditions forecast for Big Rock over the next 16 days.
The Lowdown
G’day, Rusty here. We’ve got a good look at the next couple of weeks for Big Rock, and it’s a real mixed bag. Let’s get into it.
Right off the bat, the first few days are a total loss. Sunday and Monday are just blown-out with strong onshore winds and messy, stormy surf. It’s big, pushing 10 to 16 feet, but it’s an absolute mess. Not worth paddling out.
It settles a bit on Tuesday the 18th. There’s some serious swell, around 14 feet, with a long 16-second period, but it’s still got a cross-onshore wind on it, making it lumpy. The energy is moderate at 9072. You might get a few, but it won't be fun.
Now, here’s the one you’ve been waiting for. Friday the 21st is the standout. The morning has a clean 13-foot SW swell with a cross-off breeze, but the afternoon is the real deal. The wind drops to glassy and the swell builds to a solid 15 feet, with a very long 17-second period. It’s a monster, with strong energy at 10302, and it’s going to be perfect reef waves. This is strictly for the experts—big, powerful, and raw. It’ll be a session you remember.
The weekend after that is a letdown. Saturday and Sunday still have some fun, head-high-plus waves around 8 feet, but the period drops and the winds get a bit more cross-shore. It’s surfable, but not special.
The whole week after that is pretty miserable. From Monday the 24th through Thursday the 28th, we’ve got smaller swells and strong winds, mostly blowing everything out. There are a couple of marginal windows, but nothing that gets the heart racing.
But don’t write it off entirely. Look at Sunday the 30th. The forecast is for a massive, clean 13-foot SW groundswell in the morning with a light offshore wind, building in the afternoon to a solid 16 feet. The energy is off the charts at 11174. It’s far out, so don’t book your flights yet, but it's shaping up to be a proper, heavy day for the experienced crew. Put it in the back of your mind.
Rusty, out.
Short Range ForecastModerate rain (total 17mm), heaviest on Mon morning. Very mild (max 19°C on Sun afternoon, min 13°C on Mon afternoon). Winds increasing (light winds from the NE on Sat night, strong winds from the W by Mon afternoon). | Days 5-7 Weather SummaryLight rain (total 6mm), mostly falling on Wed morning. Very mild (max 16°C on Tue night, min 10°C on Thu night). Winds decreasing (fresh winds from the WNW on Tue night, calm by Fri afternoon). | ||||||||||||||||||
Sunday 16 | Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | ||||||||||||||
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) | WSW 13 | WSW 15 | WSW 14 | WSW 15 | W 14 | WSW 12 | WSW 15 | WSW 16 | WSW 16 | WSW 15 | WSW 15 | WSW 15 | WSW 16 | WSW 16 | WSW 16 | SW 15 | SW 15 | SW 17 | SW 16 |
Wave Graph  | |||||||||||||||||||
 kJ | 1619 | 3427 | 3151 | 3144 | 5180 | 7789 | 9930 | 9072 | 8511 | 5615 | 6993 | 9006 | 10445 | 8769 | 6609 | 7663 | 6137 | 10302 | 5788 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross | cross | on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on | on | on | cross-on | cross-off | cross-off | glassy | cross-off |
High Tide | 00:00AM0.59m | 10:48AM0.62m | 11:55PM0.64m | 10:00AM0.54m | 00:10AM0.70m | 00:37AM0.74m | 1:15AM0.78m | 2:08AM0.81m | 3:39AM0.84m | ||||||||||
Low Tide | 5:05AM0.52m | 5:10PM0.47m | 6:30AM0.52m | 4:12PM0.44m | 3:35PM0.38m | 3:25PM0.34m | 3:31PM0.30m | 3:41PM0.29m | |||||||||||
 |  | |  |  |  |  |  | | | | |  |  | | | | | | |
 | — | 6:58 | — | — | 6:56 | — | — | 6:56 | — | — | 6:54 | — | — | 6:54 | — | — | 6:52 | — | — |
 | 5:49 | — | 5:50 | — | — | 5:51 | — | — | 5:52 | — | — | 5:52 | — | — | 5:52 | — | — | 5:53 | — |
mm | — | — | — | 1 | 13 | 2 | 1 | — | — | 3 | 3 | — | — | — | — | — | — | — | — |
Temp °C | 17 | 17 | 19 | 19 | 18 | 14 | 14 | 14 | 15 | 16 | 16 | 15 | 15 | 15 | 15 | 14 | 12 | 15 | 14 |
Feels °C | 16 | 11 | 13 | 15 | 11 | 4 | 6 | 10 | 9 | 8 | 11 | 12 | 12 | 9 | 9 | 10 | 8 | 12 | 11 |
Swell 1 Height (m) Direction Period (s) | WSW 13 | WSW 15 | WSW 14 | WSW 15 | SW 18 | — | WSW 15 | WSW 16 | WSW 16 | WSW 15 | WSW 15 | WSW 15 | WSW 16 | WSW 16 | WSW 16 | SW 15 | SW 15 | SW 17 | SW 16 |
| kJ | 1619 | 3427 | 3151 | 3144 | 1944 | — | 9930 | 9072 | 8511 | 5615 | 6993 | 9006 | 10445 | 8769 | 6609 | 7663 | 6137 | 10302 | 5788 |
Swell 2 Height (m) Direction Period (s) | WSW 16 | SW 24 | SW 22 | SW 20 | NNW 7 | — | — | — | — | — | — | — | — | — | — | — | SW 19 | — | — |
| kJ | 886 | 142 | 563 | 1394 | 163 | — | — | — | — | — | — | — | — | — | — | — | 3119 | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | NNE 6 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | 64 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | N 4 | N 6 | NNW 6 | W 14 | WSW 12 | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | 36 | 198 | 148 | 5180 | 7789 | — | — | — | — | — | — | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 53 | 159 | 53 | 1339 | 633 | 2 | 38 | 202 | 251 | 359 | 20 | 20 | 2 | 2 | 1 | 0 | 0 | 0 |
Best forecast wave conditions in Margaret River | |||||||||||||||||||
Best forecast wave conditions in Australia | |||||||||||||||||||
Header Global | |||||||||||||||||||
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Information about the Big Rock Surf forecast
The above surf forecast table for Big Rock provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Big Rock can be found by selecting the local surf guide option on the grey menu. Our Big Rock 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 (Big Rock) 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 Big Rock 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.
Big Rock is 85 km (53 miles) from the city of Bunbury. If you plan a holiday in Margaret River, look for hotels and other accommodation in Bunbury. Bunbury has rooms for a wide range of budgets as well as car hire and transport links.
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