{"id":331,"date":"2026-06-09T15:15:19","date_gmt":"2026-06-09T13:15:19","guid":{"rendered":"https:\/\/dortokai.eu\/guides\/how-to-read-a-surf-forecast\/"},"modified":"2026-06-09T15:15:19","modified_gmt":"2026-06-09T13:15:19","slug":"how-to-read-a-surf-forecast","status":"publish","type":"guide","link":"https:\/\/dortokai.eu\/en\/guides\/how-to-read-a-surf-forecast\/","title":{"rendered":"How to read a surf forecast (and what foiling changes)"},"content":{"rendered":"<p>Before every session, there&rsquo;s a ritual: open the app and scan the numbers. But there&rsquo;s a world between \u00ab\u00a0looking at the forecast\u00a0\u00bb and \u00ab\u00a0knowing how to read it\u00a0\u00bb \u2014 and when you switch to foiling, the parameters that matter change again. Here&rsquo;s how to decode a surf forecast.<\/p>\n<h2>Swell: far more than just height<\/h2>\n<p>Most people look at the height and stop there. That&rsquo;s the classic mistake. A swell reads across several data points:<\/p>\n<ul>\n<li><strong>Height<\/strong> \u2014 the size of the waves offshore. The most-watched, the least meaningful on its own.<\/li>\n<li><strong>Period<\/strong> \u2014 the time, in seconds, between two wave trains. The key number. Short (under 8 s) = wind swell, messy and soft. Long (12 s and up) = ground swell born far offshore: powerful, organised, peeling. Two 1 m swells have nothing in common if one is at 6 s and the other at 14 s.<\/li>\n<li><strong>Direction<\/strong> \u2014 where the swell comes from. Depending on how the spot faces, the same swell can deliver everything\u2026 or never come in.<\/li>\n<li><strong>Swell energy<\/strong> \u2014 the metric on the rise, in kJ\/m\u00b2. It combines height and period into one value and reflects the real power reaching the coast. At equal height, two swells of different periods carry very different energy \u2014 often a far better indicator than height alone of whether \u00ab\u00a0it&rsquo;ll push\u00a0\u00bb.<\/li>\n<\/ul>\n<h2>Wind: what makes or breaks the session<\/h2>\n<p>Two things matter: its strength and its direction.<\/p>\n<ul>\n<li><strong>Offshore<\/strong> (land to sea): smooths the surface, hollows the waves, holds them. The ideal wind \u2014 a whisper of offshore transforms a session.<\/li>\n<li><strong>Onshore<\/strong> (sea to land): chops the surface, softens everything. Too much onshore and the waves turn shapeless.<\/li>\n<li><strong>Cross-shore<\/strong> (sideways): in between, depending on the spot&rsquo;s orientation and the strength.<\/li>\n<\/ul>\n<p>A light, well-oriented wind (5 to 10 knots) is perfect; beyond 15 to 20 knots of onshore, most spots close out. Wind shifts through the day: the calmer morning windows are precious.<\/p>\n<h2>Tide: the parameter everyone forgets<\/h2>\n<p>Many spots only work at a certain tide, or a precise window. The same spot can be perfect at mid rising tide and unrideable two hours later. Tide changes the depth, and therefore how the wave breaks on the bottom. Check the tide coefficient and times for your spot.<\/p>\n<h2>Ratings aren&rsquo;t an absolute truth<\/h2>\n<p>Classic trap: blindly trusting the rating (stars, a score out of 10) shown by the sites. These ratings are largely subjective, and above all calibrated for an experienced surfer after powerful, well-formed waves. Surfline&rsquo;s, Windguru&rsquo;s or surf-forecast&rsquo;s \u00ab\u00a0good\u00a0\u00bb isn&rsquo;t necessarily yours.<\/p>\n<p>A beginner will have a blast in small mushy waves rated \u00ab\u00a0poor\u00a0\u00bb. A foiler will find gold in 50 cm that every site calls \u00ab\u00a0flat\u00a0\u00bb. Learn to read the raw data rather than the rating, and build your own scale \u2014 based on your level, your gear and what you enjoy.<\/p>\n<h2>What foiling changes<\/h2>\n<p>In foiling, reading the forecast takes on another dimension. Three parameters become critical:<\/p>\n<ul>\n<li><strong>Wind, differently.<\/strong> You ride far smaller, softer conditions than in surfing: a 50 cm swell becomes rideable. So you chase light-wind windows and the small swells surfers ignore. In wingfoiling it&rsquo;s the opposite: wind is exactly what you want.<\/li>\n<li><strong>Water depth.<\/strong> The parameter unique to foiling: a mast and wings reach down 70\u201390 cm. Too little water \u2014 low tide, a rising bottom, a sandbar \u2014 and the foil hits the bottom: gear damage and a violent fall. Check the depth at the relevant tide.<\/li>\n<li><strong>Currents.<\/strong> You drift from the peak, pump, cover ground. A current pushing out to sea or toward the rocks is something to anticipate before you paddle out.<\/li>\n<\/ul>\n<h2>The tools: data, ratings\u2026 and webcams<\/h2>\n<p>For swell, wind and tide, each service has its strengths:<\/p>\n<ul>\n<li><strong>Windguru<\/strong> \u2014 the data reference, dense and reliable.<\/li>\n<li><strong>Windy<\/strong> \u2014 the animated map, perfect for visualising wind and fronts.<\/li>\n<li><strong>Surfline<\/strong> \u2014 strong on premium spots, expert forecasts and plenty of webcams.<\/li>\n<li><strong>surf-forecast<\/strong> \u2014 handy for a spot-by-spot read.<\/li>\n<\/ul>\n<p>And don&rsquo;t forget webcams: many spots have one, freely accessible. Nothing beats a live look at the real state of the sea before you load the car \u2014 data predicts, the webcam confirms.<\/p>\n<p>For foiling, these tools don&rsquo;t cross-reference everything (swell, wind, tide, depth) from a foiler&rsquo;s point of view: a foil-focused resource like <a href=\"https:\/\/foil-viewer.ovh?utm_source=dortokai&utm_medium=guide&utm_content=how-to-read-a-surf-forecast\" target=\"_blank\" rel=\"noopener\">foil-viewer.ovh<\/a> helps you spot the right windows.<\/p>\n<h2>A concrete example: Hendaye vs Seignosse<\/h2>\n<p>Take two neighbouring spots and the same data: a swell energy of around 1200\u20131500 kJ\/m\u00b2.<\/p>\n<p>At Hendaye, a bay sheltered at the bottom of the coast, that energy gives accessible conditions: the swell arrives filtered, the bay takes the edge off it. The result \u2014 easily surfable and foilable, even at a beginner-to-intermediate level.<\/p>\n<p>At Seignosse, an exposed beach break facing the open ocean, the same energy is a whole other story: the swell hits unfiltered, the sets are powerful, the currents strong. At 1200\u20131500 kJ, the spot is reserved for experienced surfers.<\/p>\n<p>Same number, two opposite realities. That&rsquo;s exactly why a universal rating means nothing \u2014 and why knowing your spot&rsquo;s personality is worth more than any forecast.<\/p>\n<h2>The real secret: study your spot<\/h2>\n<p>No forecast replaces knowing a spot. The data describes what arrives offshore; your spot turns that data into real waves, depending on its bottom, its sandbars and its exposure \u2014 the Hendaye \/ Seignosse example shows it well. The only real way to understand a spot and find your best windows is to study it, session after session:<\/p>\n<ul>\n<li><strong>Tides<\/strong> \u2014 at what tide it opens and closes.<\/li>\n<li><strong>Currents (rips)<\/strong> \u2014 where it pulls, where it creates channels. Useful for paddling smart, essential for your safety.<\/li>\n<li><strong>Wave formation<\/strong> \u2014 how the swell wakes up on a given sandbar or shoal, where the peak forms and how it shifts with size and direction.<\/li>\n<\/ul>\n<p>Sandbars move, the bottom changes: a spot is never fixed. Keeping a session journal \u2014 the day&rsquo;s conditions (swell, period, energy, wind, tide) and what it actually delivered \u2014 is one of the most effective ways to build that knowledge. Tools like <a href=\"https:\/\/foil-viewer.ovh?utm_source=dortokai&utm_medium=guide&utm_content=how-to-read-a-surf-forecast\" target=\"_blank\" rel=\"noopener\">foil-viewer.ovh<\/a> also help you keep track of your sessions and cross-reference conditions with how it felt. Over time, you read your spot better than any app.<\/p>\n<p>Reading a forecast well is already half of a good session. The rest is knowing your spot and being ready once you&rsquo;re in the water \u2014 with <a href=\"\/en\/guides\/how-to-choose-a-foil-leash\/\">the right gear<\/a>, to stay focused on what matters: the ride.<\/p>","protected":false},"excerpt":{"rendered":"<p>Swell, period, energy, wind, tide: how to really read a surf forecast, why ratings are subjective, what foiling demands, and why knowing your spot beats everything.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"inline_featured_image":false,"guide_lang":"en","guide_pair":"330","rank_math_title":"How to read a surf forecast (and what foiling changes) | dortokai","rank_math_description":"Swell, period, energy, wind, tide: how to really read a surf forecast, why ratings are subjective, what foiling demands, and why knowing your spot beats everything."},"class_list":["post-331","guide","type-guide","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/dortokai.eu\/en\/wp-json\/wp\/v2\/guide\/331","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dortokai.eu\/en\/wp-json\/wp\/v2\/guide"}],"about":[{"href":"https:\/\/dortokai.eu\/en\/wp-json\/wp\/v2\/types\/guide"}],"wp:attachment":[{"href":"https:\/\/dortokai.eu\/en\/wp-json\/wp\/v2\/media?parent=331"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}