
Surf Forecasts:
Siriu surf forecast from 9 Sep 2026:
- Best quality surf: Saturday 12 Sep, 12PM (local time) - 10ft (3.0m), 10s period, S swell with cross-offshore winds.
- Most powerful swell: Saturday 12 Sep, 12PM (local time) - 10ft (3.0m), 10s period, S swell with 1,684 kJ wave energy.
- Next surfable swell (1★+): Wednesday 9 Sep, 12AM (local time) - 3.5ft (1.1m), 9s period with SSE 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 Wednesday (Sep 09) at 12AM. The primary swell is predicted to be 1.1m and 9s period with a secondary swell of 0.8m and 6s. The wind is predicted to be 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 Saturday (Sep 12) at 12PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 6s period and expected on Wednesday (Sep 16) at 3AM.
| Wave Type | Time (-03) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Wed 9th Sep) | 3.5ft (1.1m) 9s |
| Best Surf | 12PM (Sat 12th Sep) | 10ft (3.0m) 10s |
| Most Powerful | 12PM (Sat 12th Sep) | 10ft (3.0m) 10s |
Table - best surf conditions forecast for Siriu over the next 16 days.
The Lowdown
G’day, Rusty here. Let’s have a proper look at what’s on the cards for Siriu. The first few days are pretty grim, so don’t rush to wet a line just yet. The outlook is poor until around the 12th, so if you’re keen, that’s a good stretch to do some odd jobs or fix your board.
We start on Tuesday the 8th with clean but tiny waves. There’s nothing doing—just over 3ft of short-period swell with a cross-on breeze making it messy. Not worth the paddle out. Wednesday the 9th is a bit better early with glassy conditions and a touch more energy, but it’s still small and weak. The window is tight and the waves are ordinary.
Thursday and Friday are pretty poor. The wind is all over the shop, mostly cross or onshore, and the swell is weak and slow. There’s a bit of energy on Thursday afternoon, but it’s still lumpy and hard to ride. Friday is worse with rain showers and wind. You’d be fighting it the whole time.
Now, pay attention—Saturday the 12th is where things get real. The swell jumps up to 10ft, and the energy reading is massive (3700). That’s a solid wall of water. But here’s the catch: at this size, Siriu is too big for most. The wind is cross-off and the surface is clean, so it’s looking like a session for the experienced crew only. If you’re not comfortable in heavy water, give it a miss. Sunday the 13th is a big standout though. The swell backs off to a much more manageable 6ft, with light cross-off winds and clean conditions. The energy is still solid (559), and this looks like the pick of the week. Get on it early, maybe a bit on the push.
Monday the 14th turns ugly again with fresh onshores and rain. Not great. Tuesday the 15th is better though, with clean, cross-off winds and head-high sets of 7ft in the morning. The energy is strong (1149). It’s a proper surf day, but not as clean as Sunday. Still, a morning session looks very good.
From the 16th through to the 19th it becomes very up and down. Mostly small and weak with poor wind. A highlight is Friday the 18th morning—clean, glassy-ish, with a 4ft swell and decent period. It’s rideable, but nothing to brag about. The weekend of the 19th and 20th is again poor with onshore winds and small, messy waves.
The following week, from the 20th to the 22nd, is generally small and weak. There are moments of clean conditions, but the waves are just too ordinary to get excited about. The 21st might offer a few waist-high waves with cross-off wind, but it’s marginal at best. The 22nd is small and clean-ish but very weak.
The last day in the window, Wednesday the 23rd morning, is interesting. There’s a glassy start with a 2ft swell and a bit of period. It’s tiny, but the surface will be like a mirror. If you just want to get wet and aren’t fussed about size, it could be a fun one. Afternoon goes onshore, so it’ll chop right out.
So, to sum it up, your standout days are Sunday the 13th and Tuesday the 15th. The 13th is the best overall for clean, powerful surf. The 12th is for the brave only. Otherwise, it’s a drought until then.
Right, I’m off to check the tide charts.
Rusty.
Short Range ForecastHeavy rain (total 26mm), heaviest during Fri afternoon. Warm (max 23°C on Fri morning, min 15°C on Tue night). Wind will be generally light. | Days 5-7 Weather SummaryHeavy rain (total 27mm), heaviest during Mon afternoon. Warm (max 20°C on Fri night, min 15°C on Fri night). Winds decreasing (fresh winds from the SW on Fri night, calm by Mon afternoon). | ||||||||||||||||||
Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | ||||||||||||||
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 9 | SSE 10 | SSE 12 | S 12 | S 12 | SSE 15 | SSE 13 | NE 8 | ENE 8 | NE 8 | S 10 | S 10 | SSE 10 | SE 10 | SE 10 | ESE 7 | SE 9 | S 11 | SE 8 |
Wave Graph | |||||||||||||||||||
197 | 209 | 288 | 284 | 184 | 456 | 225 | 196 | 90 | 169 | 998 | 1601 | 867 | 710 | 739 | 297 | 199 | 229 | 206 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | glassy | cross-on | glassy | cross | cross | cross | cross | cross | cross-off | cross-off | cross-off | cross | cross | on | on | on | glassy | glassy |
High Tide | 00:22AM0.62m | 2:10PM0.77m | 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 | |||||||
Low Tide | 7:16AM-0.05m | 7:51PM0.32m | 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 | |||||||
— | 6:18 | — | — | 6:18 | — | — | 6:16 | — | — | 6:16 | — | — | 6:15 | — | — | 6:13 | — | — | |
6:02 | — | 6:04 | — | — | 6:04 | — | — | 6:05 | — | — | 6:05 | — | — | 6:06 | — | — | 6:06 | — | |
mm | — | — | — | 2 | — | — | 1 | 2 | 21 | — | — | — | 2 | 1 | 2 | 2 | 7 | 13 | 9 |
Temp °C | 17 | 19 | 18 | 17 | 19 | 21 | 19 | 23 | 23 | 20 | 17 | 17 | 16 | 16 | 16 | 16 | 15 | 15 | 16 |
Feels °C | 17 | 19 | 18 | 18 | 20 | 22 | 18 | 22 | 21 | 20 | 12 | 12 | 14 | 14 | 14 | 13 | 12 | 15 | 16 |
Swell 1 Height (m) Direction Period (s) | SSE 9 | E 7 | E 8 | E 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | NE 8 | ENE 8 | SSE 10 | SSE 10 | SE 10 | SE 10 | ESE 7 | SE 9 | SE 9 | SE 8 |
197 | 134 | 142 | 157 | 133 | 133 | 158 | 128 | 90 | 169 | 47 | 1130 | 867 | 710 | 739 | 297 | 199 | 196 | 206 | |
Swell 2 Height (m) Direction Period (s) | ENE 6 | SSE 10 | SSE 12 | S 12 | S 12 | SSE 15 | SSE 13 | S 12 | S 12 | E 12 | E 12 | ENE 8 | ENE 8 | ENE 8 | ENE 9 | S 10 | ENE 6 | S 11 | ENE 7 |
56 | 209 | 288 | 284 | 184 | 456 | 225 | 103 | 67 | 3 | 3 | 72 | 53 | 38 | 61 | 279 | 55 | 229 | 70 | |
Swell 3 Height (m) Direction Period (s) | SSE 15 | SSE 10 | SE 9 | E 15 | SSE 16 | E 14 | E 14 | E 13 | ESE 13 | E 12 | — | — | — | S 13 | ENE 9 | ENE 8 | SSE 11 | ENE 7 | SSE 10 |
21 | 86 | 20 | 4 | 144 | 4 | 4 | 13 | 17 | 12 | — | — | — | 51 | 86 | 50 | 156 | 88 | 160 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | N 5 | NE 8 | NNE 5 | S 11 | S 10 | S 10 | — | — | — | — | ENE 7 | — | — |
— | — | — | — | — | — | 76 | 196 | 38 | 114 | 998 | 1601 | — | — | — | — | 153 | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 27 | 0 | 0 | 16 | 0 | 16 | 9 | 0 | 9 | 27 | 68 | 15 | 38 | 0 | 0 | 16 | 16 | 458 | 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.










