
Surf Forecasts:
Siriu surf forecast from 10 Sep 2026:
- Best quality surf: Tuesday 15 Sep, 12AM (local time) - 10ft (3.0m), 9s period, ENE swell with glassy winds.
- Most powerful swell: Tuesday 15 Sep, 12AM (local time) - 10ft (3.0m), 9s period, ENE swell with 1,204 kJ wave energy.
- Next surfable swell (1★+): Thursday 10 Sep, 12AM (local time) - 3.5ft (1.0m), 12s 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 Thursday (Sep 10) at 12AM. The primary swell is predicted to be 1.0m and 12s period with a secondary swell of 1.1m and 8s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Siriu in the next 16 days are 3.0m 9s and forecast to arrive on Tuesday (Sep 15) at 12AM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 6s period and expected on Saturday (Sep 12) at 3AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Thu 10th Sep) | 3.5ft (1.0m) 12s |
| Best Surf | 12AM (Tue 15th Sep) | 10ft (3.0m) 9s |
| Most Powerful | 12AM (Tue 15th Sep) | 10ft (3.0m) 9s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Yo, it's Rusty here, and I've gotta be straight with you—this 16-day stretch for Siriu is a bit of a mixed bag. There's a lot of so-so conditions to wade through, but there are a couple of sessions that'll make it worth hanging up your work boots.
The first decent window doesn't arrive until Saturday, the 12th. The early part of the week is ruled out by messy, marginal surf. From Thursday the 10th through Friday the 11th, it's small, crossed-up, and just not worth the paddle. We're looking at a couple of days of nothing good to start.
Then Saturday morning the 12th brings a bit of hope. A 7ft swell out of the south with a period of 9 seconds rolls in. The combined wave energy is moderate (1234). The wind is a clean cross-off from the southwest at 16 mph, which is a major positive—it'll scrub the surface up nicely. The break is out of the east, so this south swell has some exposure. It's probably a bit much for beginners at that size, but for the rest of you, it's the first real look. Crowds are sometimes a thing here, so you might have some company.
Sunday the 13th is a write-off in the afternoon with onshore winds, but Tuesday the 15th is your standout. Tuesday morning shows clear skies and a 6ft swell from the east. The wind is light and cross-off from the southwest. The combined energy is 767. That's clean, glassy potential and the best quality of the run so far.
Looking further out, Wednesday the 16th morning has a decent 7ft south swell (1146 combined energy) with cross-off winds, but the afternoon turns a bit choppy. Not bad, but not the top pick.
The real jewel in the crown looks to be Friday the 25th of September. That's over two weeks away, so take it with a grain of salt, but the data is promising. A 7ft easterly swell with a 9-second period and light, cross-off winds from the northwest. The combined energy hits 803. The forecast confidence is lower this far out, but if it lines up, this could be the cleanest, most powerful day of the whole outlook. Keep an eye on it.
For the gaps: after the 16th, we get another flat spell through to the 20th with tiny, onshore junk. The 21st has a glassy morning but small swell. By the 22nd and 23rd, it's back to weak and ordinary.
So, my pick for the best on offer is Tuesday morning the 15th for that clean, east swell, and the long-range standout to circle is Friday the 25th—just don't book any time off work for it yet.
Rusty.
Short Range ForecastHeavy rain (total 30mm), heaviest during Fri afternoon. Warm (max 22°C on Thu afternoon, min 16°C on Wed night). Winds increasing (calm on Wed night, fresh winds from the SSW by Fri night). | Days 5-7 Weather SummaryHeavy rain (total 40mm), heaviest during Sun night. Warm (max 20°C on Tue morning, min 14°C on Sat night). Wind will be generally light. | ||||||||||||||||||
Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | ||||||||||||||
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 12 | S 12 | SSE 15 | SSE 13 | NE 8 | ENE 8 | ENE 8 | S 9 | SSE 8 | SSE 8 | SE 8 | SE 8 | SE 8 | ENE 7 | ENE 7 | ENE 9 | E 9 | E 8 | S 8 |
Wave Graph | |||||||||||||||||||
284 | 184 | 456 | 225 | 186 | 142 | 119 | 708 | 434 | 394 | 126 | 164 | 142 | 168 | 468 | 1204 | 567 | 283 | 466 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | cross | cross-on | glassy | cross | cross-on | cross-off | cross-off | cross | cross-off | cross-off | on | cross-on | on | on | glassy | cross-off | cross | cross-off |
High Tide | 00:43AM0.70m | 2:10PM0.72m | 1:11AM0.77m | 2:12PM0.69m | 1:42AM0.80m | 2:21PM0.67m | 2:14AM0.81m | 2:36PM0.66m | 2:48AM0.78m | 2:54PM0.65m | 3:23AM0.73m | 3:13PM0.63m | |||||||
Low Tide | 7:52AM-0.05m | 8:12PM0.30m | 8:25AM-0.01m | 8:30PM0.27m | 8:55AM0.05m | 8:43PM0.24m | 9:19AM0.14m | 8:48PM0.21m | 9:36AM0.23m | 8:47PM0.18m | 9:26AM0.32m | 8:54PM0.17m | |||||||
— | 6:18 | — | — | 6:16 | — | — | 6:16 | — | — | 6:15 | — | — | 6:13 | — | — | 6:11 | — | — | |
6:04 | — | 6:04 | — | — | 6:05 | — | — | 6:05 | — | — | 6:06 | — | — | 6:06 | — | — | 6:07 | — | |
mm | 1 | 1 | — | 8 | 6 | 14 | — | — | — | — | — | 3 | 17 | 12 | 6 | 2 | — | — | 1 |
Temp °C | 17 | 19 | 22 | 19 | 20 | 21 | 20 | 18 | 18 | 15 | 16 | 17 | 16 | 16 | 15 | 15 | 20 | 18 | 16 |
Feels °C | 18 | 20 | 23 | 22 | 21 | 23 | 21 | 14 | 14 | 12 | 14 | 16 | 14 | 12 | 12 | 14 | 18 | 15 | 14 |
Swell 1 Height (m) Direction Period (s) | E 8 | E 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | S 8 | ENE 8 | SSE 8 | SE 8 | SE 8 | SE 8 | ENE 7 | E 7 | E 9 | E 9 | E 8 | ENE 8 |
157 | 121 | 131 | 110 | 110 | 142 | 119 | 465 | 68 | 284 | 126 | 164 | 142 | 114 | 277 | 805 | 567 | 283 | 94 | |
Swell 2 Height (m) Direction Period (s) | S 12 | S 12 | SSE 15 | SSE 13 | S 12 | S 11 | SSE 11 | ENE 8 | SE 12 | ENE 8 | S 7 | ENE 8 | S 10 | SE 8 | SSE 11 | SSE 10 | SSE 11 | SSE 11 | — |
284 | 184 | 456 | 225 | 103 | 66 | 39 | 47 | 6 | 53 | 88 | 54 | 96 | 93 | 194 | 108 | 167 | 156 | — | |
Swell 3 Height (m) Direction Period (s) | E 15 | SSE 16 | E 14 | E 14 | E 13 | S 7 | E 12 | ESE 12 | — | E 12 | ENE 8 | SSE 11 | ENE 8 | S 9 | SE 8 | S 12 | SE 7 | — | — |
4 | 144 | 4 | 4 | 13 | 3 | 3 | 14 | — | 3 | 53 | 25 | 38 | 122 | 86 | 69 | 33 | — | — | |
Wind waves Height (m) Direction Period (s) | — | NNE 2 | NNE 4 | — | NE 8 | N 4 | SSW 3 | S 9 | SSE 8 | SSE 8 | — | — | ENE 5 | ENE 7 | ENE 7 | ENE 9 | SW 3 | S 6 | S 8 |
— | 1 | 21 | — | 186 | 28 | 2 | 708 | 434 | 394 | — | — | 21 | 168 | 468 | 1204 | 5 | 109 | 466 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 9 | 9 | 0 | 6 | 9 | 39 | 13 | 38 | 0 | 0 | 27 | 16 | 368 | 72 | 6 | 0 | 38 | 13 |
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.










