Surf Forecasts:
Siriu surf forecast from 23 Aug 2026:
- Best quality surf: Sunday 23 Aug, 9PM (local time) - 8ft (2.5m), 14s period, SSE swell with cross-offshore winds.
- Most powerful swell: Monday 24 Aug, 9AM (local time) - 8ft (2.5m), 14s period, SSE swell with 2,541 kJ wave energy.
- Next surfable swell (1★+): Sunday 23 Aug, 9AM (local time) - 5.5ft (1.7m), 11s 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 Sunday (Aug 23) at 9AM. The primary swell is predicted to be 1.7m and 11s period with a secondary swell of 0.3m and 8s. 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 2.5m 14s and forecast to arrive on Monday (Aug 24) at 9AM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 3s period and expected on Friday (Aug 28) at 3AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Sun 23rd Aug) | 5.5ft (1.7m) 11s |
| Best Surf | 9PM (Sun 23rd Aug) | 8ft (2.5m) 14s |
| Most Powerful | 9AM (Mon 24th Aug) | 8ft (2.5m) 14s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Alright, Rusty here again. Let's have a look at the next 16 days out at Siriu. The water's sitting right at 67°F, which is just about normal for the season.
The forecast has a few clean windows, but it's mostly about picking your moment. There's a big, powerful swell on the horizon for early September, but it's a week away and I'll tell you more about that in a bit.
The Weekend & Early Next Week (Aug 23-26)
Starting with Sunday morning, we have some clean conditions with a light offshore breeze and a 6ft south swell. There's not a ton of energy behind it, but it's a perfectly surfable wave for a beginner. Later in the day, it gets a little bumpier as the wind turns onshore.
Monday morning is the real deal, though. The ocean will be glassy with a solid 8ft, 14-second period swell from the south-southeast. This is a powerful groundswell with plenty of energy. The surf will be clean and lined up. It's a bit more size, so you should have some experience, but this is the pick of the first week. The crowd will be out in full force. Tuesday sees the size drop to around 6ft and the wind gets a bit tricky, making things lumpy.
Mid-Week Lull & Windy Days (Aug 27-31)
The rest of the week is a bit of a fight. Wednesday and Thursday have some bigger, longer-period swell, but the wind is strong and from the NNE, which is messing it all up. It'll be cross-chopped and blown out. Not worth the hassle. Friday drops in size and the period shortens, but the wind is still howling. It's going to be frustrating. The weekend, Aug 30 and 31, brings it right down. The swell is small, around 5ft, but it's clean. Glassy on Sunday afternoon, light winds on Monday morning. These are small, fun days, but the energy is weak.
The Second Week (Sep 1 - Sep 7)
Next week starts off clean but small, with a 5ft swell on Tuesday. But the big one is Wednesday, September 2nd. The charts are showing a serious 10ft to 12ft southerly swell with favorable light winds. The energy reading is massive. This is a big, powerful beach break, and it’s going to be way overhead. This will likely be more interesting for the kite-surfers than us paddle surfers, as it might be a bit of a washing machine at the takeoff zone. Again, it's over a week out, so this is promising, but we need to keep an eye on it. After that, it looks like it fades out. We have a few small, clean days but nothing with any power. We finish the period on Sep 7 with almost nothing on the menu.
So, to sum it up. The two standouts are Monday, Aug 24th for the clean, powerful swell, and Wednesday, Sep 2nd for the big, expert-level stuff. Pick your days, and I'll see you out there.
Rusty.
Short Range ForecastMostly dry. Very mild (max 18°C on Tue afternoon, min 10°C on Sun night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 26°C on Fri afternoon, min 17°C on Wed night). Winds decreasing (fresh winds from the NNE on Thu afternoon, light winds from the N by Fri night). | ||||||||||||||||||||
Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | |||||||||||||||
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) | S 11 | SSE 12 | SSE 13 | SSE 14 | SSE 14 | SSE 13 | SSE 13 | SSE 12 | SE 16 | SSE 15 | SSE 14 | SSE 14 | SSE 13 | SSE 13 | SSE 12 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | E 8 | E 9 |
Wave Graph | |||||||||||||||||||||
746 | 1240 | 2373 | 2541 | 2285 | 1319 | 993 | 918 | 906 | 2111 | 1835 | 1193 | 745 | 520 | 251 | 344 | 616 | 341 | 246 | 239 | 359 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-on | off | glassy | cross-on | glassy | cross | cross-on | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-off | cross-on | cross-off |
High Tide | 12:57PM0.68m | 11:53PM0.52m | 1:15PM0.72m | 00:17AM0.60m | 1:34PM0.75m | 00:41AM0.67m | 1:53PM0.77m | 1:06AM0.73m | 2:12PM0.77m | 1:33AM0.78m | 2:31PM0.76m | 2:02AM0.81m | 2:52PM0.74m | 2:33AM0.82m | |||||||
Low Tide | 6:39PM0.35m | 6:07AM0.11m | 7:01PM0.31m | 6:46AM0.04m | 7:25PM0.28m | 7:21AM-0.01m | 7:51PM0.26m | 7:55AM-0.04m | 8:17PM0.25m | 8:29AM-0.04m | 8:45PM0.24m | 9:04AM-0.02m | 9:14PM0.24m | ||||||||
6:37 | — | — | 6:37 | — | — | 6:35 | — | — | 6:35 | — | — | 6:33 | — | — | 6:33 | — | — | 6:31 | — | — | |
— | 5:55 | — | — | 5:55 | — | — | 5:57 | — | — | 5:57 | — | — | 5:58 | — | — | 5:58 | — | — | 5:59 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 | 3 |
Temp °C | 15 | 14 | 11 | 14 | 14 | 13 | 17 | 18 | 15 | 20 | 19 | 18 | 23 | 24 | 20 | 25 | 26 | 22 | 23 | 22 | 20 |
Feels °C | 12 | 10 | 7 | 12 | 11 | 12 | 14 | 14 | 12 | 17 | 17 | 16 | 20 | 21 | 18 | 23 | 25 | 22 | 24 | 24 | 23 |
Swell 1 Height (m) Direction Period (s) | S 11 | SSE 12 | SSE 13 | SSE 14 | SSE 14 | SSE 13 | SSE 13 | SSE 12 | SSE 12 | SSE 15 | SSE 14 | SSE 14 | SSE 13 | SSE 13 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | E 8 | E 9 |
746 | 1240 | 2373 | 2541 | 2285 | 1319 | 993 | 918 | 671 | 2111 | 1835 | 1193 | 745 | 520 | 128 | 344 | 404 | 341 | 246 | 239 | 359 | |
Swell 2 Height (m) Direction Period (s) | ENE 8 | ENE 8 | ENE 7 | NE 7 | — | — | — | — | SE 16 | — | — | — | NE 7 | — | SSE 12 | SSE 11 | SSE 11 | SSE 11 | SE 10 | SE 10 | SSE 10 |
13 | 6 | 5 | 2 | — | — | — | — | 906 | — | — | — | 135 | — | 251 | 115 | 81 | 44 | 27 | 25 | 9 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | S 7 |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | ENE 3 | NNE 4 | NNE 4 | NE 4 | NE 6 | NE 7 | NE 7 | N 4 | N 5 | ENE 8 | — | SW 2 | — | — |
— | — | — | — | — | — | — | 7 | 10 | 16 | 11 | 95 | 200 | 173 | 9 | 63 | 616 | — | 1 | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 13 | 0 | 0 | 13 | 0 | 9 | 27 | 9 | 27 | 26 | 27 | 27 | 101 | 109 | 27 | 16 | 6 | 25 | 16 | 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.











