Surf Forecasts:
Siriu surf forecast from 5 Sep 2026:
- Best quality surf: Sunday 6 Sep, 9PM (local time) - 10ft (3.0m), 10s period, S swell with cross-offshore winds.
- Most powerful swell: Sunday 6 Sep, 9PM (local time) - 10ft (3.0m), 10s period, S swell with 1,702 kJ wave energy.
- Next surfable swell (1★+): Saturday 5 Sep, 9PM (local time) - 4.5ft (1.3m), 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 Saturday (Sep 05) at 9PM. The primary swell is predicted to be 1.3m and 9s period with a secondary swell of 1.0m and 9s. Another secondary swell of 0.7m 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 3.0m 10s and forecast to arrive on Sunday (Sep 06) at 9PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.9m 6s period and expected on Sunday (Sep 06) at 6AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Sat 5th Sep) | 4.5ft (1.3m) 9s |
| Best Surf | 9PM (Sun 6th Sep) | 10ft (3.0m) 10s |
| Most Powerful | 9PM (Sun 6th Sep) | 10ft (3.0m) 10s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Alright folks, Rusty here, looking at the surf prospects for Siriu over the next couple of weeks.
It’s a bit of a slow start, but there’s some real grunt building for the second week. The water temp is sitting at 65.7°F, which is pretty much spot on for this time of year, so no surprises there.
The first real sniff of a decent session is Sunday morning, the 6th. The swell is pushing 6.6ft, coming from the S with a short 8-second period, which means it’ll be a bit on the fat side but the wind is a clean cross-off from the SW. The water’s got a moderate amount of energy in it (534), and it’s clean. It’s a solid option for a beginner-friendly wave, but the short period means it might not have the best shape.
We’ve got a bit of a lull mid-week, but things start to get interesting around Monday, the 14th. That’s when a proper pulse hits. We’re looking at 7.2ft from the SSE with a long 12-second period. The energy jumps right up (1391), and while the wind is a light cross-shore, it’s still manageable. That’s a proper groundswell, and at this size, it’s edging into expert territory.
The real standout window, though, is Thursday, the 17th, through to Friday, the 18th. Thursday afternoon sees a 7.5ft S swell with a 12-second period, and the energy is pumping (2439). The wind is a clean cross-off from the SSW. That’s a serious combo. Then Friday morning rolls in with a 4.9ft S swell, but the wind is light and variable, and by the afternoon it goes glassy. The energy is still strong (712 on Friday morning), and the conditions are lined up for a damn good session. The period is a bit shorter at 9-10 seconds, but the combination of clean, glassy conditions and a solid swell makes this the absolute pick of the fortnight. Keep in mind that this is a long way out, so don’t book the week off just yet, but it’s looking promising.
Crowds at Siriu can be an issue sometimes, so on those standout days, expect it to be busy.
Short Range ForecastLight rain (total 7mm), mostly falling on Sat afternoon. Warm (max 20°C on Tue morning, min 8°C on Sun night). Winds decreasing (fresh winds from the S on Sun afternoon, light winds from the ESE by Mon afternoon). | Days 5-7 Weather SummaryLight rain (total 2mm), mostly falling on Wed night. Warm (max 23°C on Wed morning, min 16°C on Tue night). Wind will be generally light. | |||||||||||||||||||
Sat 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | ||||||||||||||
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 9 | S 9 | S 8 | S 10 | S 9 | S 10 | SSE 10 | SSE 10 | SSE 10 | ENE 6 | NE 8 | ENE 8 | ENE 8 | ENE 8 | E 8 | SSE 14 | SSE 13 | ENE 8 | ENE 8 | E 8 |
Wave Graph  | ||||||||||||||||||||
 kJ | 160 | 247 | 489 | 1057 | 1153 | 489 | 383 | 455 | 258 | 156 | 574 | 314 | 266 | 197 | 161 | 276 | 176 | 112 | 181 | 129 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-off | cross-off | cross | cross-off | cross-off | on | cross-off | cross | cross-on | cross | cross | on | glassy | glassy | cross-on | glassy | cross-on | cross-on | cross |
High Tide | 00:19AM0.41m | 1:01PM0.79m | 00:24AM0.46m | 1:32PM0.82m | 00:17AM0.54m | 1:57PM0.80m | 00:22AM0.62m | 2:10PM0.77m | 00:43AM0.70m | 2:10PM0.72m | 1:11AM0.77m | 2:12PM0.69m | 1:42AM0.80m | |||||||
Low Tide | 9:01PM0.34m | 4:52AM0.16m | 6:52PM0.34m | 5:49AM0.06m | 7:07PM0.33m | 6:35AM-0.01m | 7:28PM0.33m | 7:16AM-0.05m | 7:51PM0.32m | 7:52AM-0.05m | 8:12PM0.30m | 8:25AM-0.01m | 8:30PM0.27m | |||||||
 |  |  | |  |  | | | | |  | | |  |  | |  | |  | | |
 | — | — | 6:22 | — | — | 6:22 | — | — | 6:20 | — | — | 6:18 | — | — | 6:18 | — | — | 6:16 | — | — |
 | 6:01 | — | — | 6:02 | — | — | 6:02 | — | — | 6:02 | — | — | 6:04 | — | — | 6:04 | — | — | 6:05 | — |
mm | 6 | 1 | — | — | — | — | — | — | — | — | — | — | — | 2 | — | — | — | — | 2 | 15 |
Temp °C | 14 | 14 | 13 | 13 | 11 | 13 | 14 | 14 | 20 | 20 | 16 | 23 | 21 | 18 | 19 | 19 | 19 | 21 | 19 | 21 |
Feels °C | 12 | 11 | 6 | 5 | 5 | 10 | 12 | 12 | 16 | 16 | 15 | 23 | 22 | 19 | 20 | 20 | 19 | 20 | 17 | 19 |
Swell 1 Height (m) Direction Period (s) | S 9 | S 8 | E 8 | ENE 8 | S 9 | S 10 | SSE 10 | SSE 10 | SSE 10 | SSE 9 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | E 8 | E 8 | E 8 | ENE 8 | ENE 8 | E 8 |
| kJ | 160 | 138 | 31 | 13 | 763 | 489 | 383 | 455 | 258 | 156 | 344 | 314 | 266 | 197 | 161 | 157 | 137 | 112 | 112 | 129 |
Swell 2 Height (m) Direction Period (s) | ENE 8 | ENE 8 | E 9 | — | E 8 | E 8 | E 8 | E 8 | E 6 | SE 12 | SSE 9 | SSE 12 | SSE 12 | S 10 | S 12 | SSE 14 | SSE 13 | S 12 | S 11 | S 11 |
| kJ | 92 | 68 | 14 | — | 5 | 5 | 5 | 10 | 96 | 38 | 124 | 246 | 237 | 73 | 141 | 276 | 176 | 72 | 64 | 37 |
Swell 3 Height (m) Direction Period (s) | SE 10 | SE 10 | — | — | — | — | — | ENE 8 | — | S 16 | SSE 15 | SSE 11 | SSE 9 | SSE 13 | SSE 16 | E 14 | E 14 | SSE 5 | SSE 5 | ESE 12 |
| kJ | 28 | 16 | — | — | — | — | — | 12 | — | 5 | 21 | 65 | 16 | 90 | 95 | 4 | 4 | 9 | 9 | 15 |
Wind waves Height (m) Direction Period (s) | — | S 9 | S 8 | S 10 | S 9 | — | — | — | ENE 6 | ENE 6 | NE 8 | — | — | — | SSW 2 | — | — | — | ENE 8 | NE 5 |
| kJ | — | 247 | 489 | 1057 | 1153 | — | — | — | 140 | 139 | 574 | — | — | — | 1 | — | — | — | 181 | 30 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 10 | 0 | 13 | 458 | 10 | 0 | 27 | 0 | 6 | 16 | 6 | 6 | 16 | 0 | 0 | 13 | 0 | 9 | 16 | 43 |
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.
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