A forecast can help you choose a session, although the biggest number on the screen is rarely the whole story. Two days with similar wave heights can feel very different once swell period, direction, wind and the shape of the beach enter the picture.
Think of your forecast as a starting point for checking the ocean. Around Dominical, your coach’s local knowledge and a few minutes watching the beach help connect those numbers to the conditions you will actually surf.
Start by checking what the height measures
Swell height and breaking surf height describe different things. Swell height refers to waves traveling through the ocean, while a surf-height prediction estimates what may break at a particular spot. A forecast showing a small swell does not automatically promise small, gentle waves at the beach.
Look at the units, the spot and the label before comparing two forecasts. Then consider your own ability rather than treating a green rating or a favorable description as a recommendation for every surfer.
Read period and direction together
Period is the time between successive waves in a swell, measured in seconds. Longer-period swells can carry more energy and behave differently as they approach shallow water. The same swell height with a longer period may produce a more powerful session, depending on the break.
Direction tells you where a swell is coming from. A beach’s orientation and surrounding coastline affect how much of that swell reaches the lineup, so a direction that works well at one spot may have a different result nearby.
| Forecast detail | Useful question |
|---|---|
| Height | Is this swell height or predicted breaking surf? |
| Period | Could this swell feel more powerful than its height suggests? |
| Direction | How exposed is this beach to that swell? |
| Wind | What will the wind do at the time I plan to surf? |
| Tide | How does this particular break change with the tide? |
Wind changes the surface; tide changes the setup
Onshore wind blows toward land and often makes waves less clean. Offshore wind blows away from land and can help shape the face, although strong offshore wind can also make paddling and catching waves difficult. Light wind may be more useful to a learner than a strong wind with a favorable label.
Tide is another local question. There is no single best tide for every Costa Rica beach, and a tide that improves a wave for an experienced surfer may not make it appropriate for a beginner. Sandbanks can change, which is another reason to keep checking the actual beach.
Walk through an example
Illustrative forecast, not current conditions: 1 m swell, 16-second period, southwest direction, light onshore wind and a rising tide.
| What you read | What to do with it |
|---|---|
| 1 m swell | Check whether the app means offshore swell or predicted breaking surf; they aren’t interchangeable |
| 16 seconds | Expect a longer-period swell to behave differently from a short-period swell of the same height |
| Southwest | Ask how exposed the selected beach is to energy from that direction |
| Light onshore wind | Check the actual surface and whether the wind is increasing |
| Rising tide | Use the tide time alongside the current sandbar, entry and exit |
For Dominical, that combination calls for watching several sets and the current before choosing a peak. A first-timer should discuss the lesson window at Dominicalito with their coach, even if the app gives the coast a favorable rating. The numbers alone don’t approve a paddle-out.
Build a small record of your own sessions
After surfing, note the forecast, what you saw and how the session felt. Include the time, beach, wind and your coach’s observations. Over several sessions, you will start recognizing which combinations support your current goals.
Before your next lesson, bring the forecast and ask why your coach chose that location and time. Learning to make that connection is useful long after the holiday ends.
Keep those observations in a two-minute session log and compare them with our Dominical-area beach guide. You’ll learn more by connecting a few sessions than by memorizing one “perfect” forecast.
Sources and further reading
Technical references used for this guide. Forecasts and general etiquette should be combined with local conditions and instruction.