Surf Forecasts:
Flatrock surf forecast from 20 Aug 2026:
- Best quality surf: Saturday 22 Aug, 6PM (local time) - 8ft (2.5m), 15s period, SW swell with glassy winds.
- Most powerful swell: Thursday 20 Aug, 6PM (local time) - 10ft (3.0m), 16s period, SW swell with 4,474 kJ wave energy.
- Next surfable swell (1★+): Saturday 22 Aug, 6PM (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 6PM. The primary swell is predicted to be 2.5m and 15s period with a secondary swell of 0.9m and 20s. 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 Thursday (Aug 20) at 6PM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (ACST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6PM (Sat 22nd Aug) | 8ft (2.5m) 15s |
| Best Surf | 6PM (Sat 22nd Aug) | 8ft (2.5m) 15s |
| Most Powerful | 6PM (Thu 20th Aug) | 10ft (3.0m) 16s |
Table - best surf conditions forecast for Flatrock over the next 16 days.
The Lowdown
G’day, I’m Rusty. Let’s have a look at what’s shaping up for Flatrock over the next couple of weeks.
We’ve got a lumpy start, but there’s a real standout morning on Sunday, 23 August that’s worth getting excited about. The water temp is sitting at 59°, which is pretty much bang on average for this time of year, so no surprises there.
The first few days are a bit of a write-off. Thursday, 20 August through to Saturday, 22 August are all cross-onshore winds with solid swell around 7 ft to 10 ft from the SW, but the conditions are poor to marginal. The wave energy is strong though, with readings between 2923 and 4595, so there’s plenty of power, just not the clean face we want.
Then Sunday, 23 August morning rolls in and it’s a different story. The wind swings to a light NNE cross-off at 9 mph, and the swell is still a solid 8 ft from the SW with a very long 17-second period. That’s proper groundswell, and for a reef like Flatrock, that long period should wrap in nicely. The energy is pumping at 3459, and the forecast says excellent conditions for experienced surfers. This is the pick of the window—clean, powerful, and lined up. Keep in mind this is a bit further out, so it’s promising but not locked in yet.
Sunday afternoon turns rougher again, and Monday, 24 August drops off to a smaller 5 ft with lighter winds, but the energy drops to 1038, making it pretty average. Tuesday, 25 August sees a bump back up to 8 ft from the SW, but it’s cross-shore winds and messy.
Wednesday, 26 August is smaller again, and then Thursday, 27 August afternoon brings a bigger pulse—12 ft from the SW with a 19-second period and energy at 7822. The wind is cross-shore moderate, but the surf is still marginal. Friday, 28 August morning has a strong 25 mph NNE cross-off keeping it clean, but 12 ft is only for the experts.
The rest of the run from Saturday, 29 August into early September is mostly poor or marginal, with strong winds and lumpy seas. There’s a sniff of something on Tuesday, 1 September with a smaller 5 ft SW swell and light winds, but it’s cross-onshore and nothing special.
Bottom line: if you’re keen, pencil in Sunday, 23 August morning. That’s the one that’s got the goods—clean, solid, and long-period. The rest is a mixed bag.
Rusty.
Short Range ForecastMostly dry. Very mild (max 15°C on Thu morning, min 12°C on Thu night). Winds decreasing (fresh winds from the WNW on Thu morning, calm by Sat afternoon). | Days 4-6 Weather SummaryMostly dry. Very mild (max 15°C on Sun afternoon, min 11°C on Tue night). Wind will be generally light. | ||||||||||||||||||||
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) | SW 16 | SW 16 | SW 15 | SW 15 | SW 16 | SW 16 | SW 15 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 14 | SW 14 | SW 17 | SW 15 | SW 14 | SW 13 | SW 13 | SW 12 | SW 16 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2242 | 2612 | 3402 | 2668 | 3865 | 4084 | 3330 | 2919 | 2148 | 3459 | 2545 | 1325 | 978 | 743 | 1334 | 3051 | 2201 | 1299 | 796 | 570 | 1513 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | on | cross-off | cross-off | cross-on | glassy | on | cross-on | cross | cross | cross | glassy | cross | cross-on | cross-off |
High Tide | 2:10PM0.34m | 4:32AM0.40m | 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 | ||||||||||
Low Tide | 9:36AM0.24m | 9:04PM0.01m | 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 | |||||||||
 |  |  |  | |  | | | | | | | | | | | |  | | | | |
 | 7:03 | — | — | 7:01 | — | — | 7:01 | — | — | 7:00 | — | — | 6:58 | — | — | 6:58 | — | — | 6:56 | — | — |
 | — | 6:00 | — | — | 6:00 | — | — | 6:01 | — | — | 6:02 | — | — | 6:02 | — | — | 6:04 | — | — | 6:05 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 15 | 14 | 13 | 13 | 14 | 15 | 13 | 13 | 13 | 14 | 15 | 15 | 15 | 15 | 13 | 13 | 13 | 13 | 11 | 12 | 13 |
Feels °C | 9 | 8 | 9 | 9 | 10 | 11 | 11 | 11 | 12 | 10 | 12 | 14 | 13 | 13 | 9 | 8 | 9 | 11 | 7 | 9 | 8 |
Swell 1 Height (m) Direction Period (s) | SW 16 | SW 16 | SW 15 | SW 15 | SW 16 | SW 16 | SW 15 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 | SW 15 | SW 14 | SW 13 | SW 13 | SW 12 | SW 16 |
| kJ | 2242 | 1983 | 3402 | 2668 | 3865 | 4084 | 3330 | 2919 | 2148 | 3459 | 2545 | 1325 | 978 | 743 | 1147 | 3051 | 2201 | 1299 | 796 | 570 | 1513 |
Swell 2 Height (m) Direction Period (s) | — | — | SW 20 | SW 18 | — | S 26 | SW 23 | SW 21 | SW 19 | — | — | SW 21 | SW 20 | SW 18 | SW 17 | — | SSW 13 | SSW 13 | SW 18 | SSW 16 | SW 23 |
| kJ | — | — | 392 | 1019 | — | 13 | 140 | 664 | 1268 | — | — | 18 | 60 | 162 | 1334 | — | 102 | 367 | 80 | 179 | 84 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SW 18 | SW 16 | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 152 | 260 | — |
Wind waves Height (m) Direction Period (s) | WSW 10 | SW 16 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | NW 3 | — |
| kJ | 681 | 2612 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 4 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 221 | 692 | 198 | 153 | 294 | 126 | 74 | 153 | 0 | 0 | 44 | 0 | 42 | 126 | 152 | 153 | 197 | 0 | 42 | 42 | 44 |
Best forecast wave conditions in Eyre Peninsula | |||||||||||||||||||||
Best forecast wave conditions in Australia | |||||||||||||||||||||
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Flatrock surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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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