Flatrock Surf Break

Lat Long: 34.68° S 135.32° E

Flatrock Surf Forecast and Surf Report

Issued: 8 am 17 Aug 2026 (local time)

Forecast update in  hr  min

Today's Flatrock sea temperature is
14.9° C
0.1° 

Flatrock surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.


Flatrock surf forecast from 17 Aug 2026:

  • Best quality surf: Friday 21 Aug, 12AM (local time) - 8ft (2.5m), 15s period, SW swell with glassy winds.
  • Most powerful swell: Friday 21 Aug, 9AM (local time) - 8ft (2.5m), 17s period, SW swell with 4,151 kJ wave energy.
  • Next surfable swell (1★+): Monday 17 Aug, 9PM (local time) - 5.5ft (1.7m), 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 Monday (Aug 17) at 9PM. The primary swell is predicted to be 1.7m and 15s period with a secondary swell of 1.1m and 20s. The wind is predicted to be cross-offshore as the swell arrives.

The most powerful waves expected at Flatrock in the next 16 days are 2.5m 17s and forecast to arrive on Friday (Aug 21) 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 0.7m 4s period and expected on Monday (Aug 17) at 6PM.

Wave TypeTime (ACST) & Date Wave Height & Period
Next good surf (1 star+) 9PM (Mon 17th Aug)5.5ft (1.7m) 15s
Best Surf12AM (Fri 21st Aug)8ft (2.5m) 15s
Most Powerful 9AM (Fri 21st Aug)8ft (2.5m) 17s

Table - best surf conditions forecast for Flatrock over the next 16 days.


The Lowdown

Alright, this is Rusty, checking in with a look at the surf ahead for Flatrock.

We’ve got a solid run of swell on the way, but it’s not all smooth sailing. The action kicks off right away on Monday the 17th, but let’s be honest, the conditions are a bit of a mixed bag early on. The real magic is waiting for you later in the week and into the following one.

First up, Flatrock is a reef break and it’s for the advanced crew only. Right out of the gate on Monday morning the 17th, we’ve got a decent 6ft SW groundswell with a long 16-second period pumping in. The water’s sitting at 59°, which is pretty much what you’d expect for this time of year. That offshore breeze from the east is keeping things clean, and the wave energy is strong at 2072. But Monday afternoon gets a bit messy with a cross-off wind, and then Tuesday the 18th is a write-off with a cross-shore wind messing it up. Wednesday the 19th is a total no-go with onshore winds blowing it out.

Now, hang tight through that midweek chop, because Thursday the 20th is a bit of a tease with light cross-onshore winds, but the swell is still solid at 7ft. The real standout is shaping up for Friday morning the 21st. We’re looking at a significant 8ft SW swell with a 17-second period, and the wave energy is pumping hard at 6146. Winds are just a light cross-onshore breeze, so it’s still gonna be okay. But keep your eyes on Saturday morning the 22nd. That’s the pick of the early run. The swell holds at 8ft from the SW with a 15-second period, and we get glassy conditions with a breath of a WNW wind. This is as good as it gets for clean, powerful waves. It’s big enough to be for experienced surfers only.

Sunday the 23rd is another glassy morning with 8ft SW swell and zero wind. Another cracker, just a touch smaller. Then we get a bit of a slump early the next week with onshores picking up and the swell dropping to 6ft on Monday the 24th.

But the second week is where the heavy stuff comes back. By Thursday the 27th, the swell is back up to a powerful 10ft from the SW (wave energy at 6163) but with a fresh offshore breeze from the NNE keeping it clean. That’s a solid day for the experts. Then into the final stretch, the pay-off arrives. Friday morning the 28th is a belter: an 12ft SW swell with a 10-second period, but with a light offshore wind from the east keeping it perfect. The energy is well into the strong range at 3266. Even better, Friday afternoon the 28th sees the swell push to 13ft from the SW with a 12-second period, and a clean cross-off breeze. This is big, powerful, and clean – a proper session for the experienced crew. Saturday the 29th morning cleans up nicely with a 10ft SW swell and offshore winds too. It stays surfable right through to Monday the 1st of September, though the winds turn onshore and chop it up by Tuesday.

So, to wrap it up: the best bets are the glassy mornings on Saturday the 22nd and Sunday the 23rd for a solid, clean swell, and then the heavyweight sessions on Friday the 28th and Saturday the 29th for the big, clean, powerful stuff. Don’t bother with the midweek chop.

Stay salty,
Rusty.

Short Range Forecast

Light rain (total 4mm), mostly falling on Tue night. Very mild (max 17°C on Tue afternoon, min 12°C on Mon night). Winds decreasing (fresh winds from the W on Tue night, light winds from the W by Wed night).

Days 4-6 Weather Summary

Mostly dry. Very mild (max 15°C on Sat morning, min 13°C on Thu night). Wind will be generally light.

Monday
17
Tuesday
18
Wednesday
19
Thursday
20
Friday
21
Saturday
22
Sunday
23
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
4
3
3
3
1
0
0
0
1
3
2
5
5
3
4
5
4
5
5
3
1
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
1.9
SW
16
1.8
SW
16
1.7
SW
15
1.8
SW
17
1.5
SW
16
1.3
SW
16
1.3
SW
15
2
WSW
11
2.3
SW
14
2.1
SW
16
2
SW
16
2.5
SW
15
2.5
SW
17
2.5
SW
17
2.5
SW
16
2.5
SW
15
2.5
SW
16
2.5
SW
15
2.4
SW
14
2.4
SW
16
2
SW
15
Wave Graph
Metric surfscale
Energy kJ
1852
1622
1212
1837
1187
834
799
892
1837
2061
1968
2945
4151
4007
3483
2972
3090
2612
2416
2905
1695
Wind (km/h)
20
E
20
NE
20
NNE
25
NNE
25
N
35
WNW
30
W
25
W
20
WNW
10
NW
15
W
5
WSW
10
SW
10
SW
10
SW
5
WNW
10
W
0
W
0
NNW
10
W
15
WSW
Wind State
off
cross-off
cross-off
cross-off
cross
cross-on
on
on
on
cross-on
on
glassy
cross-on
cross-on
cross-on
glassy
on
glassy
glassy
on
on
High Tide
2:15PM0.42m
2:55AM0.47m
2:20PM0.39m
3:24AM0.46m
2:21PM0.36m
3:55AM0.44m
2:10PM0.34m
4:32AM0.40m
1:32PM0.34m
5:45AM0.35m
11:40AM0.42m
Low Tide
8:27PM0.01m
8:52AM0.13m
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
part cloud
rain showers
clear
clear
part cloud
rain showers
part cloud
cloud
part cloud
part cloud
part cloud
clear
clear
clear
clear
part cloud
clear
part cloud
cloud
part cloud
rain showers
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
7:07
7:05
7:05
7:03
7:01
7:01
7:00
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
5:58
5:59
6:00
6:00
6:00
6:01
6:02
 mm
1
3
1
Temp °C
14
13
13
16
17
15
14
14
14
14
14
14
14
14
14
15
15
14
13
14
14
Feels °C
11
9
10
12
11
9
7
9
10
12
12
13
12
12
12
13
13
12
12
12
11
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
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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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