Using Surf-Forecast’s Historical Surf Data To Find The Most Consistent Waves On Earth
Using our statistical data for 7000 spots dating back to 2006, we can find those waves that break the most, with the best winds.
Surf Forecasts:
Siriu surfForecast / Santa Catarina – Sul / Brazil
48hr Weather and Surf, issued 2 am Thursday 18 Dec 2025 -03Forecast update in hr min s Forecast update imminent
Siriu surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Siriu sea temperature is
24.2° C
(Which is normal for this time of year)How big are the waves at Siriu today?
The current surf forecast for Siriu at 7AM is: 1.0m 9s primary swell from a South direction and 0.5m 8s secondary swell from a East-northeast direction, 0.2m 3s secondary swell from a North-northeast direction (forecast issued at 02:00am December 18). The wind direction is predicted to be cross-shore.
| Time (-03) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (18 Dec) | 3.5ft (1.0m) | 9s |
| Afternoon (18 Dec) | 3ft (0.9m) | 8s |
| Evening (18 Dec) | 2ft (0.6m) | 8s |
Table - waves today at Siriu. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Thursday 18 | Friday 19 | Saturday 20 | ||||||||||||||||||||||
| 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    | |||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 10 | 10 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 262 | 221 | 168 | 160 | 127 | 107 | 66 | 47 | 32 | 23 | 23 | 23 | 84 | 40 | 32 | 23 | 22 | 33 | 41 | 42 | 56 | 55 | 57 | 72 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross | cross- off | cross- off | cross | cross- on | cross- on | cross- on | cross | cross | cross- off | cross- off | cross- on | cross- on | cross- on | cross- on | cross- on | cross | cross | cross | cross- on | cross- on | cross- on | cross- on | cross- on |
High Tide / height (m) | 12:32PM 0.59 | 1:48AM 0.73 | 1:02PM 0.61 | 2:19AM 0.74 | 1:33PM 0.64 | |||||||||||||||||||
Low Tide / height (m) | 7:39AM 0.30 | 7:19PM 0.07 | 8:16AM 0.31 | 7:55PM 0.05 | 8:50AM 0.32 | 8:33PM 0.03 | ||||||||||||||||||
Thursday 18 | Friday 19 | Saturday 20 | ||||||||||||||||||||||
| Sunrise | - | - | 5:13 | - | - | - | - | - | - | - | 5:13 | - | - | - | - | - | - | - | 5:13 | - | - | - | - | - |
| Sunset | - | - | - | - | - | - | 7:07 | - | - | - | - | - | - | - | 7:07 | - | - | - | - | - | - | - | 7:08 | - |
 | |  | | | | | | | | | | | | | | |  | | | | | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 19 | 18 | 18 | 22 | 25 | 25 | 23 | 20 | 19 | 19 | 19 | 25 | 27 | 26 | 24 | 22 | 21 | 21 | 21 | 24 | 26 | 26 | 24 | 22 |
| Feels °C (?) | 17 | 16 | 16 | 19 | 21 | 22 | 21 | 19 | 18 | 18 | 18 | 24 | 25 | 24 | 23 | 22 | 21 | 22 | 21 | 23 | 23 | 24 | 22 | 21 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
Latest Updates
Nazare Big Wave Challenge Gets Yellow Alert, Could Run Saturday in Giant Waves
70-foot plus waves predicted for Portuguese big wave tow surfing competition.
Buy Less, Surf More This Black Friday
Surf-forecast is providing a free, all-access pass to our premium features and 12-day forecasts all weekend.
Quiksilver Teams Up With PrimaLoft® For World’s First Thermal Layering System for a Wetsuit.
Previously used in our snow jackets for mountain conditions, PrimaLoft® technology is making its debut in the surf industry. The aim is to bring mountain-grade warmth to the waves.
Read more
Discover more articles and updates in the Greenroom.
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Siriu surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Nearest