Surf Forecasts:
Siriu surf forecast from 15 Sep 2026:
- Best quality surf: Monday 21 Sep, 12AM (local time) - 7ft (2.2m), 8s period, NE swell with glassy winds.
- Most powerful swell: Sunday 20 Sep, 6PM (local time) - 7ft (2.2m), 8s period, ENE swell with 666 kJ wave energy.
- Next surfable swell (1★+): Tuesday 15 Sep, 9PM (local time) - 2.5ft (0.7m), 10s 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 Tuesday (Sep 15) at 9PM. The primary swell is predicted to be 0.7m and 10s period with a secondary swell of 0.7m and 8s. Another secondary swell of 0.6m and 6s 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 2.2m 8s and forecast to arrive on Sunday (Sep 20) at 6PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 4s period and expected on Tuesday (Sep 15) at 3PM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Tue 15th Sep) | 2.5ft (0.7m) 10s |
| Best Surf | 12AM (Mon 21st Sep) | 7ft (2.2m) 8s |
| Most Powerful | 6PM (Sun 20th Sep) | 7ft (2.2m) 8s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
Hey crew, Rusty here. Let's break down what Siriu has to offer over the next 16 days.
We kick off with some small, short-period SSE swell on Tuesday the 15th. The morning has a clean 3ft wave, but it drops off and gets choppy by the afternoon. The clear standout in the first week is Wednesday morning, the 16th. You're looking at clean, glassy 5ft surf from the SSE with light SW winds. The energy is moderate (298) and it's a solid window for a beginners' wave at Siriu. Water temp is 62°, which is more than 4° colder than average, so dig out the extra rubber.
From Thursday the 17th, things go a bit sideways. Cross-onshore winds and chop take over. The swell sticks around but the quality tanks. There's a small window Sunday morning the 20th with a bigger 6ft ENE swell, but cross-shore winds will chop it up. The energy is strong though (477).
Rolling into the second week, the pattern stays mixed. Monday the 21st offers another clean morning with glassy conditions and 5ft ENE swell—decent energy (384) and good lines for the beach break. Then the wind swings back onshore for a few days, keeping the surf messy in the 3-4ft range.
Looking further out to the end of the month, there's a huge pulse of long-period SSE groundswell on Monday the 28th and Tuesday the 29th. Forecasts show 5ft+ waves with periods over 15 seconds and energy readings over 1000 (1331 on Monday afternoon). That's a lot of power, but it's a long way off, so keep your expectations in check. The wind looks mostly cross-onshore or cross-shore with chop, which is a real shame for such a clean, long-period swell. This is strictly for experts if it cleans up, as the size will be pushing 5ft with a very long period.
The pick of the whole run? Wednesday morning the 16th for the clean, glassy conditions. Monday morning the 21st is another good shout for a clean 5ft wave. The end of the month has the biggest energy, but don't bet on the wind being your friend.
Keep an eye on the charts.
- Rusty
Short Range ForecastMostly dry. Very mild (max 19°C on Thu afternoon, min 13°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 43mm), heaviest during Fri night. Warm (max 24°C on Sun morning, min 17°C on Fri morning). Wind will be generally light. | ||||||||||||||||||||
Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | Monday 21 | |||||||||||||||
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) | SSE 8 | SSE 10 | S 10 | SSE 8 | S 9 | S 10 | S 8 | S 8 | SSE 10 | SSE 10 | SSE 9 | NE 6 | ENE 7 | NE 7 | ENE 7 | ENE 8 | ENE 8 | NE 8 | ENE 8 | E 9 | ENE 9 |
Wave Graph  | |||||||||||||||||||||
 kJ | 120 | 139 | 94 | 245 | 342 | 499 | 140 | 144 | 345 | 169 | 118 | 134 | 153 | 119 | 327 | 419 | 418 | 632 | 376 | 355 | 311 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross | cross-off | glassy | cross | cross-off | cross-on | cross-on | cross | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross | cross | glassy | glassy | cross-on | cross |
High Tide | 3:13PM0.63m | 4:00AM0.66m | 3:33PM0.60m | 4:42AM0.58m | 3:51PM0.57m | 5:37AM0.51m | 12:07PM0.54m | 11:52PM0.30m | 12:05PM0.59m | 11:20PM0.37m | 12:15PM0.64m | 11:19PM0.46m | 12:28PM0.69m | 11:34PM0.55m | |||||||
Low Tide | 9:26AM0.32m | 8:54PM0.17m | 8:51AM0.38m | 9:10PM0.18m | 8:38AM0.43m | 9:29PM0.22m | 8:21AM0.46m | 2:52PM0.52m | 9:45PM0.29m | 9:41PM0.37m | 3:45AM0.24m | 5:46PM0.40m | 4:51AM0.17m | 5:58PM0.35m | |||||||
 |  |  |  | | | | | | |  |  |  | |  |  |  |  | | |  | |
 | 6:11 | — | — | 6:11 | — | — | 6:09 | — | — | 6:09 | — | — | 6:07 | — | — | 6:07 | — | — | 6:05 | — | — |
 | — | 6:07 | — | — | 6:07 | — | — | 6:07 | — | — | 6:07 | — | — | 6:08 | — | — | 6:08 | — | — | 6:08 | — |
mm | — | — | — | — | — | — | — | — | — | — | 2 | 9 | 8 | 10 | 11 | 1 | 1 | 1 | — | — | — |
Temp °C | 17 | 16 | 15 | 18 | 17 | 15 | 18 | 19 | 16 | 17 | 18 | 18 | 18 | 18 | 19 | 24 | 23 | 21 | 23 | 22 | 20 |
Feels °C | 14 | 14 | 13 | 15 | 13 | 13 | 15 | 15 | 14 | 16 | 17 | 17 | 16 | 16 | 18 | 24 | 23 | 23 | 24 | 23 | 23 |
Swell 1 Height (m) Direction Period (s) | SSE 8 | SE 8 | SE 8 | SSE 8 | S 9 | S 10 | S 8 | S 8 | SSE 10 | SSE 10 | SSE 9 | NE 7 | S 9 | E 7 | SSE 12 | SSE 13 | ENE 8 | ENE 8 | ENE 8 | E 9 | ENE 9 |
| kJ | 120 | 132 | 50 | 245 | 220 | 499 | 140 | 144 | 345 | 169 | 118 | 61 | 40 | 92 | 29 | 32 | 418 | 380 | 376 | 355 | 311 |
Swell 2 Height (m) Direction Period (s) | SE 8 | SSE 10 | S 10 | E 7 | E 7 | E 7 | S 11 | SSE 11 | E 7 | E 5 | ESE 9 | E 6 | SSE 13 | SSE 9 | SSE 8 | S 12 | SSE 12 | S 11 | S 10 | S 9 | S 9 |
| kJ | 69 | 139 | 94 | 38 | 38 | 26 | 63 | 97 | 8 | 19 | 29 | 47 | 18 | 25 | 7 | 25 | 27 | 9 | 8 | 7 | 6 |
Swell 3 Height (m) Direction Period (s) | E 8 | E 8 | E 7 | SE 8 | SSE 14 | E 12 | E 7 | E 7 | E 11 | ESE 10 | — | SSE 9 | ESE 10 | SSE 13 | E 12 | S 8 | — | — | — | — | S 12 |
| kJ | 34 | 32 | 40 | 15 | 41 | 11 | 17 | 16 | 9 | 19 | — | 88 | 10 | 34 | 3 | 1 | — | — | — | — | 3 |
Wind waves Height (m) Direction Period (s) | SSW 2 | S 4 | S 6 | — | S 9 | — | — | ENE 2 | NE 4 | NNE 4 | E 6 | NE 6 | ENE 7 | NE 7 | ENE 7 | ENE 8 | NE 8 | NE 8 | — | — | — |
| kJ | 1 | 26 | 41 | — | 342 | — | — | 1 | 10 | 6 | 31 | 134 | 153 | 119 | 327 | 419 | 305 | 632 | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 10 | 0 | 0 | 15 | 0 | 9 | 27 | 9 | 9 | 9 | 9 | 16 | 16 | 16 | 9 | 9 | 0 | 0 | 25 | 9 |
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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