Surf Forecasts:
Flatrock surf forecast from 21 Aug 2026:
- Best quality surf: Thursday 27 Aug, 6PM (local time) - 10ft (3.0m), 18s period, SW swell with cross-offshore winds.
- Most powerful swell: Tuesday 25 Aug, 9AM (local time) - 11ft (3.5m), 15s period, SW swell with 6,287 kJ wave energy.
- Next surfable swell (1★+): Saturday 22 Aug, 9PM (local time) - 8ft (2.5m), 15s 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 2.5m and 15s period with a secondary swell of 1.4m 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 3.5m 15s and forecast to arrive on Tuesday (Aug 25) at 9AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 3s period and expected on Monday (Aug 24) at 3AM.
| Wave Type | Time (ACST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Sat 22nd Aug) | 8ft (2.5m) 15s |
| Best Surf | 6PM (Thu 27th Aug) | 10ft (3.0m) 18s |
| Most Powerful | 9AM (Tue 25th Aug) | 11ft (3.5m) 15s |
Table - best surf conditions forecast for Flatrock over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s break down what’s on the menu at Flatrock. This is a reef break that needs a solid SW groundswell to get going, and it’s really only for the experienced crew – it can get heavy out there. The water temp is right around 59°F, which is totally normal for this time of year, nothing out of the ordinary.
We’ve got a messy start. From Friday the 21st through the weekend, there’s solid 8ft SW groundswell with a very long 15-16 second period, pushing through some serious energy (3687 to 3721). The catch: wind is cross-onshore or onshore, so it’s going to be choppy and lumpy. Not a fun paddle. That long period might make it break a bit straight over this reef, but that’s the nature of a big groundswell. Crowds are possible here sometimes, but with these winds, it’ll be quiet.
Monday the 24th looks brighter. The swell drops to around 5ft, still from the SW with a 14-second period, and moderate energy (962). The big win is offshore wind from the E at 12 mph, giving us clean conditions. A little rain, but the surf will be good for the experienced surfer. This is a solid early window.
Then things get nasty. Tuesday the 25th – forget it. 12ft SW swell with a fresh cross-onshore wind, lumpy and dangerous. That’s big wave territory, experts only.
From Wednesday the 26th to Friday the 28th, it’s hit or miss. Wednesday is cross-shore and average. Thursday has a crazy long 21-second period from the SW, but it’s small (4ft) and the wind is strong cross-shore. Not great. But Friday morning, August 28 – that’s the gold. We’ve got 8ft SW swell with 16 seconds of period, and the wind is light cross-offshore from the NE at just 3 mph. The energy is strong (3349), conditions are clean, and this is the day for expert surfers to be out. The best session of the whole forecast. Friday afternoon stays clean but a little smaller.
After that, it’s a slow grind. End of August into early September shows smaller swells and more lumpy, windy days. August 31 has a very long 19-second period pulse, but onshore wind spoils it. Early September brings strong winds and messy chop – not worth the trouble.
The standout is Friday morning, August 28: Flatrock with 8ft SW swell, long 16-second period, clean cross-offshore breeze. If you’re advanced and ready for it, that’s the one. Monday the 24th is a good backup for a cleaner, smaller option.
Watch the tides, stay smart, and I’ll see you out there.
Rusty
Short Range ForecastMostly dry. Very mild (max 16°C on Sun afternoon, min 11°C on Sat night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 22mm), heaviest during Mon morning. Very mild (max 14°C on Tue afternoon, min 11°C on Mon morning). Winds decreasing (strong winds from the SSW on Mon night, light winds from the WNW by Tue night). | ||||||||||||||||||||
Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | |||||||||||||||
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) | SW 15 | SW 16 | SW 16 | SW 15 | SW 15 | SW 14 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SSW 17 | SW 15 | SW 14 | SW 14 | SW 13 | SW 13 | SW 15 | SW 21 | SW 19 | SW 18 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2668 | 3865 | 4084 | 3178 | 2880 | 2383 | 3721 | 2726 | 1576 | 902 | 671 | 4123 | 6287 | 4135 | 1919 | 1346 | 940 | 1108 | 1405 | 4280 | 5308 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | cross-on | on | cross-off | cross-off | cross-on | cross-off | off | off | cross-on | cross-on | cross-on | cross-on | cross | cross-on | cross-off | cross | cross-on | cross-off |
High Tide | 1:32PM0.34m | 5:45AM0.35m | 11:40AM0.42m | 11:50AM0.47m | 1:03AM0.20m | 12:07PM0.52m | 00:38AM0.23m | 12:27PM0.55m | 00:40AM0.28m | 12:47PM0.57m | 00:53AM0.33m | ||||||||||
Low Tide | 9:44AM0.30m | 9:08PM0.04m | 8:29AM0.35m | 8:57PM0.06m | 8:21PM0.08m | 7:44PM0.09m | 4:42AM0.16m | 7:27PM0.08m | 5:25AM0.10m | 7:24PM0.07m | 5:58AM0.06m | 7:28PM0.05m | |||||||||
 | |  |  | | |  | |  |  |  |  | | | | | | | | | | |
 | 7:01 | — | — | 7:01 | — | — | 7:00 | — | — | 6:58 | — | — | 6:58 | — | — | 6:56 | — | — | 6:54 | — | — |
 | — | 6:00 | — | — | 6:01 | — | — | 6:02 | — | — | 6:02 | — | — | 6:04 | — | — | 6:05 | — | — | 6:05 | — |
mm | — | — | — | — | — | — | — | — | — | 13 | 8 | 1 | — | — | — | — | — | — | — | — | — |
Temp °C | 12 | 14 | 15 | 13 | 13 | 13 | 15 | 16 | 16 | 11 | 13 | 13 | 13 | 14 | 13 | 13 | 13 | 13 | 16 | 19 | 19 |
Feels °C | 9 | 11 | 12 | 11 | 11 | 12 | 11 | 14 | 11 | 7 | 9 | 6 | 6 | 9 | 9 | 10 | 9 | 10 | 10 | 15 | 16 |
Swell 1 Height (m) Direction Period (s) | SW 15 | SW 16 | SW 16 | SW 15 | SW 15 | SW 14 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 | SW 13 | SW 15 | SW 14 | SW 19 | SW 18 |
| kJ | 2668 | 3865 | 4084 | 3178 | 2880 | 2383 | 3721 | 2726 | 1576 | 902 | 671 | 966 | 6287 | 4135 | 1919 | 1346 | 940 | 1108 | 1290 | 4280 | 5308 |
Swell 2 Height (m) Direction Period (s) | SW 18 | — | S 26 | SW 23 | SW 21 | SW 19 | — | — | — | SW 20 | SW 18 | — | — | — | SW 20 | SW 18 | SW 16 | SSW 24 | SW 21 | SW 14 | — |
| kJ | 1019 | — | 13 | 140 | 664 | 1696 | — | — | — | 60 | 159 | — | — | — | 15 | 81 | 371 | 55 | 1405 | 872 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SW 18 | SSW 11 | SW 24 | SE 9 | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 81 | 217 | 87 | 3 | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | NE 3 | NNW 6 | SSW 17 | SW 16 | SW 14 | — | — | — | — | NNW 4 | NW 6 | — |
| kJ | — | — | — | — | — | — | — | — | — | 5 | 88 | 4123 | 4471 | 2801 | — | — | — | — | 25 | 47 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 153 | 294 | 126 | 74 | 153 | 0 | 151 | 42 | 74 | 0 | 0 | 198 | 853 | 894 | 198 | 42 | 42 | 44 | 44 | 42 | 0 |
Best forecast wave conditions in Eyre Peninsula | |||||||||||||||||||||
Best forecast wave conditions in Australia | |||||||||||||||||||||
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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.
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