
Surf Forecasts:
Siriu surf forecast from 7 Aug 2026:
- Best quality surf: Monday 10 Aug, 9AM (local time) - 8ft (2.4m), 13s period, S swell with cross-offshore winds.
- Most powerful swell: Monday 10 Aug, 9AM (local time) - 8ft (2.4m), 13s period, S swell with 1,922 kJ wave energy.
- Next surfable swell (1★+): Friday 7 Aug, 9PM (local time) - 8ft (2.4m), 9s period with S swell.
Best Forecast Surf Conditions for Siriu this week:
The surf forecast for Siriu over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Friday (Aug 07) at 9PM. The primary swell is predicted to be 2.4m and 9s period with a secondary swell of 1.9m and 9s. Another secondary swell of 0.6m and 8s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Siriu in the next 16 days are 2.4m 13s and forecast to arrive on Monday (Aug 10) at 9AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 5s period and expected on Sunday (Aug 09) at 3AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Fri 7th Aug) | 8ft (2.4m) 9s |
| Best Surf | 9AM (Mon 10th Aug) | 8ft (2.4m) 13s |
| Most Powerful | 9AM (Mon 10th Aug) | 8ft (2.4m) 13s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Alright, let's get into it. Rusty here, and I've been looking over the numbers for Siriu. It's been a bit quiet, but the juice is coming.
The first real chance to get wet is Saturday morning, the 8th of August. There's a 6ft groundswell from the SSE, with a long period of 14 seconds and a solid kick of energy (combined energy of 1192). The wind is a light cross from the north, so it's a start, but not perfect. Sunday afternoon sees a bigger 8ft swell from the south, with an 11-second period and clean cross-offshore winds. It's a step up in size, but the conditions are still a little raw.
Now, the standout. Monday the 10th of August. First light, you'll see 8ft of S swell, a 13-second period, and a gentle cross-offshore breeze. The combined energy is a massive 3233 – that's a lot of power. This is the best on offer for the first week. The water is about 67°F, which is pretty normal for this time of year.
Tuesday the 11th is a close second. The swell drops to 6ft, but the wind goes glassy. Absolutely flat calm. That's a beautiful thing – you'll get clean, smooth faces all morning. The SSE swell is still holding a 13-second period, so the waves will have shape and grunt.
Things quieten down after that. Thursday the 14th still has clean 5ft swell with glassy conditions in the morning, but the energy is fading. By Sunday the 16th, it's poor, with strong cross-onshore winds and a messy surface. We'll have a few days of not much.
Then, a long-range look. Mark your calendar for Tuesday the 18th of August. The forecast is promising but not locked in. We see a 7ft swell from the ENE, but with a short 8-second period. However, the wind is forecast to be glassy again. That's a big if for a short-period swell, but if it holds, it could be a fun morning.
The real brute shows up on Thursday the 20th of August. A 13ft S swell with a 12-second period and a combined energy of 6988. That is enormous. The wind is forecast to be light in the morning, but the swell is far too big for this spot – it's a day for the experts only. Everyone else stays on the sand.
Friday the 21st sees the swell drop to 8ft from the SSE, but the wind is onshore and messy. It's a rough finish.
If you're a beginner, look at the 14th of August – 5ft with clean conditions is a good spot to learn. For the experienced crew, Monday the 10th is the one to go for. The 20th of August is for the brave. Siriu is a fairly consistent break, so these windows are reliable, but those long-range bigger days are always a bit of a gamble.
Rusty out.
Short Range ForecastLight rain (total 8mm), mostly falling on Sun morning. Very mild (max 18°C on Sat afternoon, min 11°C on Sun afternoon). Wind will be generally light. | Days 5-7 Weather SummaryHeavy rain (total 31mm), heaviest during Wed morning. Very mild (max 18°C on Thu morning, min 12°C on Mon night). Wind will be generally light. | |||||||||||||||||||
Fri 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | ||||||||||||||
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) | S 8 | S 10 | SSE 14 | SSE 14 | S 13 | S 8 | S 11 | S 11 | S 13 | S 12 | SSE 12 | SSE 13 | SSE 12 | SSE 12 | SSE 12 | SSE 12 | SSE 12 | SSE 14 | SSE 16 | SSE 14 |
Wave Graph | ||||||||||||||||||||
432 | 656 | 1139 | 1034 | 1009 | 388 | 1188 | 1107 | 1922 | 1866 | 1047 | 1104 | 1002 | 1159 | 933 | 706 | 583 | 1032 | 1437 | 1061 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | glassy | cross | cross | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | glassy | glassy | cross | cross-off | cross | cross | cross | cross | cross-off |
High Tide | 00:27AM0.42m | 1:03PM0.75m | 00:42AM0.45m | 1:43PM0.81m | 00:39AM0.49m | 2:19PM0.83m | 00:41AM0.55m | 2:47PM0.81m | 00:59AM0.63m | 3:02PM0.76m | 1:25AM0.70m | 3:05PM0.70m | 1:55AM0.76m | |||||||
Low Tide | 5:46PM0.34m | 5:03AM0.19m | 6:53PM0.31m | 6:02AM0.10m | 7:33PM0.30m | 6:52AM0.01m | 8:05PM0.31m | 7:36AM-0.05m | 8:33PM0.34m | 8:17AM-0.08m | 8:57PM0.36m | 8:54AM-0.06m | 9:18PM0.37m | |||||||
— | — | 6:50 | — | — | 6:50 | — | — | 6:50 | — | — | 6:48 | — | — | 6:48 | — | — | 6:47 | — | — | |
5:47 | — | — | 5:47 | — | — | 5:49 | — | — | 5:49 | — | — | 5:50 | — | — | 5:50 | — | — | 5:51 | — | |
mm | — | — | 1 | 1 | — | 2 | 2 | 2 | — | — | — | — | 3 | 12 | 9 | 5 | 1 | 1 | 4 | 3 |
Temp °C | 17 | 14 | 15 | 18 | 18 | 14 | 12 | 11 | 13 | 14 | 13 | 13 | 12 | 13 | 14 | 14 | 16 | 18 | 19 | 18 |
Feels °C | 12 | 11 | 12 | 17 | 19 | 9 | 8 | 8 | 9 | 9 | 9 | 11 | 11 | 12 | 13 | 12 | 14 | 17 | 17 | 17 |
Swell 1 Height (m) Direction Period (s) | ENE 8 | S 10 | SSE 14 | SSE 14 | SSE 13 | SSE 12 | S 10 | SSE 11 | SSE 13 | S 12 | SSE 12 | SSE 13 | SSE 12 | SSE 12 | SSE 12 | SSE 12 | SSE 12 | SSE 14 | SSE 16 | SSE 14 |
69 | 656 | 1139 | 1034 | 762 | 333 | 464 | 792 | 1288 | 1233 | 1047 | 1104 | 1002 | 1159 | 933 | 706 | 583 | 1032 | 1437 | 1061 | |
Swell 2 Height (m) Direction Period (s) | — | ENE 8 | ENE 8 | — | ENE 7 | ENE 7 | SSE 11 | ENE 8 | ENE 8 | ENE 9 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 7 | — | — | SSE 16 | NE 6 |
— | 34 | 49 | — | 104 | 42 | 229 | 32 | 23 | 69 | 40 | 26 | 22 | 12 | 11 | 5 | — | — | 463 | 64 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | E 15 | ENE 7 | E 13 | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | 4 | 29 | 3 | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | S 8 | — | NE 3 | NE 8 | S 13 | S 8 | S 11 | S 11 | S 13 | S 12 | — | — | — | — | ENE 4 | ENE 4 | NE 5 | NE 6 | NE 6 | NE 6 |
432 | — | 4 | 142 | 1009 | 388 | 1188 | 1107 | 1922 | 1866 | — | — | — | — | 8 | 26 | 77 | 82 | 71 | 112 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 368 | 0 | 20 | 9 | 38 | 38 | 21 | 0 | 0 | 38 | 0 | 0 | 0 | 6 | 0 | 9 | 9 | 25 | 20 | 0 |
Best forecast wave conditions in Santa Catarina - Sul | ||||||||||||||||||||
Best forecast wave conditions in Brazil | ||||||||||||||||||||
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Information about the Siriu Surf forecast
The above surf forecast table for Siriu provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Siriu can be found by selecting the local surf guide option on the grey menu. Our Siriu 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 (Siriu) 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 Siriu 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.
Siriu is 27 km (17 miles) from Imbituba. If you plan a holiday in Santa Catarina - Sul, look for hotels and other accommodation in Imbituba. Imbituba has rooms for a wide range of budgets as well as car hire and transport links.











