Surf Forecasts:
Flatrock surf forecast from 18 Aug 2026:
- Best quality surf: Saturday 22 Aug, 9PM (local time) - 7.5ft (2.3m), 14s period, SW swell with glassy winds.
- Most powerful swell: Saturday 22 Aug, 3AM (local time) - 10ft (3.0m), 16s period, SW swell with 4,301 kJ wave energy.
- Next surfable swell (1★+): Saturday 22 Aug, 9PM (local time) - 7.5ft (2.3m), 14s period with SW swell.
Best Forecast Surf Conditions for Flatrock this week:
The surf forecast for Flatrock over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Aug 22) at 9PM. The primary swell is predicted to be 2.3m and 14s period with a secondary swell of 1.2m and 19s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Flatrock in the next 16 days are 3.0m 16s and forecast to arrive on Saturday (Aug 22) at 3AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 5s period and expected on Wednesday (Aug 19) at 12AM.
| Wave Type | Time (ACST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Sat 22nd Aug) | 7.5ft (2.3m) 14s |
| Best Surf | 9PM (Sat 22nd Aug) | 7.5ft (2.3m) 14s |
| Most Powerful | 3AM (Sat 22nd Aug) | 10ft (3.0m) 16s |
Table - best surf conditions forecast for Flatrock over the next 16 days.
The Lowdown
Alright, gang, let’s break down the next couple of weeks at Flatrock. This reef break is wide open to the southwest, so it grabs plenty of groundswell, but the wind’s gonna be a tricky partner. The water’s sitting at 59°, which is normal for this time of year, so no wetsuit worries on that front.
The first wave of the run kicks off Tuesday afternoon, August 18. There’s a solid 5ft SW groundswell with a super long 16-second period, and the energy is pumping at 1203. The wind is a moderate breeze out of the NNE, which is cross-offshore, keeping the faces clean. It’s a solid start, but the waves are on the bigger side, so this is for the experienced crew. This spot breaks fairly consistently, but it can get a few people out there on a good day.
Wednesday morning, August 19, the wind turns onshore and blows hard, so we’ll skip that. Thursday and Friday are messy with cross-onshore winds, but Friday afternoon, August 21, has a glimmer. The swell hits 8ft from the SW, period 17 seconds, and the energy is a massive 4103. The wind is a gentle cross-onshore, making it a bit choppy, but the power is real. The score is a ‘3’ for the afternoon, which is marginal, but the energy is undeniable.
Saturday, August 22, is a little better. The morning has 10ft of SW swell with a 15-second period, energy of 3666, and a light cross-onshore breeze. It’s still a bit lumpy, but the size is for experts only. The afternoon glass off with a 5 mph onshore wind and 8ft of swell is a nice window.
Now, the standout. Sunday morning, August 23. This is the one. The wind is a gentle NNE breeze, cross-offshore, and the swell is 8ft from the SW with a 16-second period. The combined energy is 3417, making for powerful, clean waves. The report says “excellent surf conditions for experienced surfers,” and I’m feeling it. The incoming tide and the long period should make for some proper, lined-up waves on this reef. This is the best on offer in the first week.
After that, it’s a bit of a lull into the middle of the week. Monday, August 24, is small and choppy. But Tuesday, August 25, brings a special treat. The morning has 5ft of SW swell, period 12 seconds, with a light offshore breeze from the east. Clean. Then the afternoon turns glassy – dead calm, no wind, with 5ft of long-period swell. That’s a true window for a paddle, even if the sets are a bit shorter. The energy is moderate at 1216, but the perfection is high.
The second week starts with a mess. Wednesday and Thursday, August 26 and 27, are blown out with strong winds and huge, lumpy swell. By Thursday afternoon, August 27, the swell hits 20ft from the SW with a 16-second period, and the energy explodes to 27476. The wind is a moderate cross-shore, but the report says the swell is too big for this break. We’re talking about a massive, dangerous ocean. Kite surfers might be in heaven, but for a paddle surfer, it’s a hard pass.
Friday and Saturday, August 28 and 29, clean up nicely. The wind goes cross-offshore and then offshore from the east, the swell drops to a manageable 10ft to 7ft, and the period stays solid. The surf is clean and powerful. Sunday, August 30, is a smaller, long-period swell with a clean cross-offshore breeze, which should be a fun, more manageable day. Monday, August 31, has a 6ft to 7ft SW swell with a 16-17 second period and a clean cross-offshore breeze. Nice.
The very end of the period, Tuesday and Wednesday, September 1 and 2, looks promising. The wind is offshore to light, the swell is around 7ft from the SW, and the period stretches out to 18 seconds on Wednesday morning. That’s a very long period groundswell, which will be best at this reef, and the energy is 2474. It’s clean and powerful.
So, the big standouts are the Sunday morning, August 23 session, and the glassy Tuesday afternoon, August 25. The second week is far less certain, but the end of the period around September 1-2 has real potential. Keep your eyes on the longer-range forecasts, but for now, get ready for the 23rd.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Tue night. Very mild (max 18°C on Tue afternoon, min 13°C on Thu night). Winds decreasing (strong winds from the WNW on Tue night, light winds from the WSW by Thu night). | Days 5-7 Weather SummaryMostly dry. Very mild (max 15°C on Mon morning, min 11°C on Sat night). Wind will be generally light. | |||||||||||||||||||
Tue 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | ||||||||||||||
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 | SW 16 | WSW 15 | SW 15 | SW 14 | SW 16 | SW 16 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 15 | SW 15 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 |
Wave Graph | ||||||||||||||||||||
1187 | 834 | 2576 | 757 | 1735 | 2080 | 1347 | 2502 | 2516 | 4103 | 4136 | 3612 | 2880 | 2148 | 3417 | 2516 | 1325 | 902 | 840 | 669 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-on | on | on | on | cross-on | on | on | cross-on | cross-on | cross-on | cross-on | on | cross-off | cross-off | cross-on | cross-off | cross-on | cross-on | cross-off |
High Tide | 3:24AM0.46m | 2:21PM0.36m | 3:55AM0.44m | 2:10PM0.34m | 4:32AM0.40m | 1:32PM0.34m | 5:45AM0.35m | 11:40AM0.42m | 11:50AM0.47m | 1:03AM0.20m | ||||||||||
Low Tide | 8:39PM0.00m | 9:16AM0.19m | 8:52PM0.00m | 9:36AM0.24m | 9:04PM0.01m | 9:44AM0.30m | 9:08PM0.04m | 8:29AM0.35m | 8:57PM0.06m | 8:21PM0.08m | 7:44PM0.09m | |||||||||
— | — | 7:05 | — | — | 7:03 | — | — | 7:01 | — | — | 7:01 | — | — | 7:00 | — | — | 6:58 | — | — | |
5:59 | — | — | 6:00 | — | — | 6:00 | — | — | 6:00 | — | — | 6:01 | — | — | 6:02 | — | — | 6:02 | — | |
mm | 1 | 4 | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 18 | 15 | 14 | 14 | 14 | 15 | 15 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 14 | 14 | 14 | 15 | 15 | 14 |
Feels °C | 13 | 10 | 7 | 8 | 9 | 10 | 11 | 12 | 11 | 10 | 10 | 11 | 11 | 12 | 10 | 11 | 13 | 13 | 13 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 16 | SW 16 | SW 15 | SW 15 | SW 14 | SW 16 | SW 16 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 15 | SW 15 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 |
1187 | 834 | 1155 | 757 | 1735 | 2080 | 1347 | 2502 | 2516 | 4103 | 4136 | 3612 | 2880 | 2148 | 3417 | 2516 | 1325 | 902 | 840 | 669 | |
Swell 2 Height (m) Direction Period (s) | SSE 10 | E 5 | — | SW 19 | SW 18 | WSW 10 | — | SW 19 | SW 18 | — | — | SSW 24 | SW 21 | SSW 19 | — | — | SW 22 | SW 20 | SW 19 | SW 18 |
9 | 4 | — | 303 | 702 | 492 | — | 940 | 1019 | — | — | 54 | 463 | 1166 | — | — | 18 | 190 | 296 | 516 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | NNW 4 | WNW 5 | WSW 15 | WSW 9 | — | — | WSW 9 | — | — | — | — | — | — | — | — | NNW 4 | — | NW 4 | WNW 4 | SW 5 |
7 | 70 | 2576 | 561 | — | — | 301 | — | — | — | — | — | — | — | — | 13 | — | 16 | 15 | 34 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 44 | 318 | 624 | 692 | 44 | 162 | 162 | 42 | 198 | 315 | 153 | 74 | 153 | 0 | 0 | 42 | 0 | 42 | 294 | 74 |
Best forecast wave conditions in Eyre Peninsula | ||||||||||||||||||||
Best forecast wave conditions in Australia | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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Information about the Flatrock Surf forecast
The above surf forecast table for Flatrock provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Flatrock can be found by selecting the local surf guide option on the grey menu. Our Flatrock 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 (Flatrock) 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 Flatrock 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.
Are you planning a holiday in Eyre Peninsula? If you are looking for accommodation near Flatrock, camping, hotels and holiday cottages in Eyre Peninsula, consider staying in Port Lincoln which is 49 km (30 miles) away.











