Surf Forecasts:
Siriu surf forecast from 3 Sep 2026:
- Best quality surf: Sunday 6 Sep, 3AM (local time) - 5ft (1.5m), 8s period, S swell with cross-offshore winds.
- Most powerful swell: Sunday 6 Sep, 9PM (local time) - 8ft (2.5m), 10s period, S swell with 1,222 kJ wave energy.
- Next surfable swell (1★+): Friday 4 Sep, 12AM (local time) - 3ft (0.9m), 11s period with SE 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 (Sep 04) at 12AM. The primary swell is predicted to be 0.9m and 11s period with a secondary swell of 0.8m and 6s. Another secondary swell of 1.2m and 5s 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 2.5m 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 0.6m 4s period and expected on Friday (Sep 04) at 9AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Fri 4th Sep) | 3ft (0.9m) 11s |
| Best Surf | 3AM (Sun 6th Sep) | 5ft (1.5m) 8s |
| Most Powerful | 9PM (Sun 6th Sep) | 8ft (2.5m) 10s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Alright, crew, Rusty here. Let’s talk about what’s on offer at Siriu.
The first few days are a bit of a bust. Thursday and Friday have some swell, but the wind is all over the place – cross and cross-onshore, making it choppy. You’re better off waiting for the weekend.
Saturday the 5th is the first real chance. We’ve got a clean 4ft swell from the south with a gentle cross-off breeze. The combined energy is moderate (429), and the period is a touch short at 8 seconds, but it’s clean and rideable for a beginner. Saturday afternoon looks the same.
Sunday the 6th drops off, and then Monday the 7th? That’s the standout in the first week. Monday morning, Siriu sees a clean 7ft swell from the SSE, with a light westerly cross-off wind. The combined energy is solid (686), and the period is a decent 9 seconds. This is the best wave of the early period. It’s getting a bit big for a total beginner, but for anyone with a bit of experience, it’s going to be fun. The water temp is about 66°, which is pretty normal for this time of year.
We then hit a long gap of poor conditions, with nothing worth paddling out for until the following week. The swell tries to build, but the winds are messy.
Now, the real gold is right at the end of the forecast. Fast forward to Friday the 18th. Both morning and afternoon are looking excellent for experienced surfers. We’re talking a 6ft to 6ft SSE groundswell with a very long period of 15 to 14 seconds. The combined energy is strong (1797). The wind is a clean cross-off from the southwest. This is a proper groundswell, so expect long lines, big energy, and longer waits between sets. It’s a powerful wave, only for experts. This is the one to circle on the calendar.
Saturday the 16th and Thursday the 17th also have some clean, glassy mornings with smaller S and SSE swell, good for a beginner to intermediate paddle if you’re keen, but the big Friday is the standout.
Stay safe out there.
Rusty.
Short Range ForecastHeavy rain (total 30mm), heaviest during Fri night. Warm (max 23°C on Thu afternoon, min 11°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummaryModerate rain (total 17mm), heaviest on Tue night. Warm (max 22°C on Wed morning, min 11°C on Sun night). Winds decreasing (fresh winds from the SSW on Sun afternoon, calm by Mon night). | |||||||||||||||||||
Thu 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | ||||||||||||||
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) | SE 11 | SE 11 | SE 10 | ENE 8 | ENE 8 | S 9 | S 9 | S 8 | S 8 | S 9 | S 9 | SSE 9 | SSE 9 | SE 9 | SE 10 | SSE 10 | ENE 6 | E 8 | NE 8 | ENE 8 |
Wave Graph  | ||||||||||||||||||||
 kJ | 344 | 198 | 108 | 69 | 96 | 122 | 126 | 368 | 219 | 798 | 541 | 547 | 397 | 388 | 365 | 205 | 170 | 174 | 191 | 287 |
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 | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | glassy | cross-on | glassy | cross-on | cross-on | cross | cross-on | cross |
High Tide | 4:44PM0.46m | 11:45PM0.33m | 11:44AM0.63m | 00:04AM0.36m | 12:25PM0.73m | 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 | ||||||
Low Tide | 9:02PM0.28m | 9:10PM0.30m | 3:36AM0.25m | 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 | ||||||||
 |  | |  |  |  | |  | | |  | | |  | | | | |  | | |
 | — | — | 6:24 | — | — | 6:24 | — | — | 6:22 | — | — | 6:22 | — | — | 6:20 | — | — | 6:18 | — | — |
 | 6:00 | — | — | 6:01 | — | — | 6:01 | — | — | 6:02 | — | — | 6:02 | — | — | 6:02 | — | — | 6:04 | — |
mm | — | — | — | 5 | 14 | 6 | 5 | — | — | — | 1 | 2 | 2 | 4 | 2 | 1 | 5 | — | — | 4 |
Temp °C | 23 | 19 | 17 | 17 | 14 | 14 | 14 | 14 | 15 | 13 | 11 | 13 | 13 | 15 | 17 | 16 | 18 | 22 | 23 | 18 |
Feels °C | 20 | 17 | 14 | 15 | 13 | 12 | 11 | 10 | 9 | 6 | 5 | 12 | 12 | 14 | 17 | 15 | 18 | 20 | 20 | 17 |
Swell 1 Height (m) Direction Period (s) | SE 11 | SE 11 | SE 10 | ENE 8 | ENE 8 | ENE 8 | S 9 | S 8 | E 8 | ENE 8 | S 9 | SSE 9 | SSE 9 | SE 9 | SE 10 | SSE 10 | SSE 9 | E 8 | E 8 | ENE 8 |
| kJ | 344 | 198 | 108 | 69 | 96 | 122 | 126 | 167 | 31 | 21 | 541 | 547 | 397 | 388 | 365 | 205 | 121 | 167 | 114 | 287 |
Swell 2 Height (m) Direction Period (s) | ENE 9 | NE 6 | NE 6 | SE 10 | S 6 | S 9 | ENE 8 | ENE 8 | SE 11 | — | E 8 | NE 8 | E 6 | ENE 8 | ENE 7 | E 6 | SSE 14 | SSE 9 | SSE 11 | SSE 10 |
| kJ | 42 | 36 | 17 | 64 | 36 | 95 | 92 | 68 | 4 | — | 12 | 2 | 39 | 6 | 5 | 49 | 21 | 65 | 138 | 82 |
Swell 3 Height (m) Direction Period (s) | — | E 8 | E 8 | S 9 | SE 10 | SE 10 | SE 10 | SE 10 | SSE 10 | — | — | — | S 18 | ENE 8 | E 8 | NE 7 | S 14 | SSE 13 | E 16 | E 16 |
| kJ | — | 36 | 34 | 2 | 63 | 37 | 36 | 16 | 10 | — | — | — | 6 | 7 | 5 | 14 | 16 | 57 | 5 | 5 |
Wind waves Height (m) Direction Period (s) | NNE 5 | NNE 5 | S 4 | S 5 | — | — | S 3 | S 8 | S 8 | S 9 | — | — | — | — | — | ENE 6 | ENE 6 | NE 7 | NE 8 | — |
| kJ | 59 | 81 | 12 | 32 | — | — | 5 | 368 | 219 | 798 | — | — | — | — | — | 106 | 170 | 174 | 191 | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 16 | 0 | 56 | 10 | 0 | 10 | 0 | 10 | 13 | 65 | 10 | 0 | 0 | 27 | 0 | 9 | 9 | 9 | 16 | 27 |
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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