When will it
be clean?
Most apps look at the wind right now. The sea has memory: a perfect offshore means nothing if 33 km/h of onshore wind dropped twenty minutes ago. Drop a pin and we will tell you what time the window opens.
Currents and sandbanks. And inside the app, what the sea has been doing for days: rip currents, the state of the sandbanks, and how the wave will break.
Leça da Palmeira
41.195, -8.710
Pick your spot
Tap the coast on the map. We work out which way the sea is and forecast the next 24 h.
Guidance only. Always judge the real conditions before you paddle out.
In the app: currents and sandbank state
We integrate what the sea has been doing on the previous days, not just the hour you are looking at. That gives a considerably sharper rating.
- · Rip current: how hard it pulls, and why (spring tide, falling, open channels).
- · Longshore drift: how many m/s, and which way it will take you.
- · Sandbanks: a storm flattens them in one tide and they take days to come back.
- · How the wave will break: soft, hollow, or straight onto the sand.
How this is calculated
It is not an average of wind speed and wave height. We integrate the state of the surface hour by hour, the way the sea actually behaves.
The sea has memory
Chop raised by onshore wind does not vanish when the wind swings. After 33 km/h of onshore wind you need roughly 3 to 6 hours of light offshore to get clean; from light texture, one or two will do. We model that as decaying energy, not a fixed rule.
The thermal land breeze
Land cools far faster than the sea. Before dawn that difference drives a light offshore that grooms the surface, and it reverses into a sea breeze in the afternoon. We use the land-versus-sea temperature difference on real solar timings, not fixed clock hours.
Groundswell versus windswell
We separate the groundswell from the locally wind-generated part, and account for period and for the angle the swell can actually reach your beach at, including the long-period energy that refracts and wraps into bays.
FAQ
What does the cleanliness score mean?
A 0 to 100 estimate of how smooth the surface will be: 100 is glass, 0 is blown out. It is independent of size, so you can have 95 cleanliness and no waves at all.
Why does my spot show so little swell when the buoy reads more?
Open-ocean wave height is not what reaches your beach. If the swell arrives at a steep angle the coastline barely sees it, and only long-period swell refracts enough to wrap in.
Where does the data come from?
Open-Meteo’s open weather and marine models: wind, gusts, air temperature, sea surface temperature, swell height and period, and tide. The cleanliness model is ours.
Can I trust it to decide whether to go?
It is a forecast, not a photo. Use it to pick the best window of the day and rule out the bad hours. Looking at the sea always gets the final say.