Reading a wind forecast for kitesurfing and sailing

For anything powered by wind, a forecast has to answer three questions at once, and a single wind speed answers none of them. Read average wind, gusts and direction together. They describe different parts of the session, and none is an equipment recommendation on its own.

The quick answer

• Average wind → the background conditions. Read it alongside gusts, direction and local observations.
• Gust spread → how much stronger short bursts may be. As an illustrative comparison, 18 knots gusting 34 calls for a different assessment from 18 gusting 22. Neither number selects a kite or makes a session suitable.
• Direction → how the wind meets the shore. Check the site-specific advice. The RNLI advises avoiding offshore winds for kitesurfing.
• The shape over time matters as much as the peak. Wind that builds steadily is a session; wind that spikes for one hour and dies is a drive for nothing.
• In Weathergraph wind is a dashed line across the hourly chart with direction arrows at each hour and double arrows where gusts are forecast — so the build, the peak and the drop are one shape rather than a table of numbers. Press and hold for the exact speed with its Beaufort name.

Why the gust gap is the number to read

Average and gust are separate forecasts of the same air. Their difference shows how far short bursts may rise above the average. It does not measure turbulence or establish a universal safe range:

Gap between average and gust	What to expect
Smaller gap	Forecast bursts are closer to the average; local conditions can still vary.
Larger gap	Assess the stronger bursts as well as the average; seek local advice on equipment.
Rapid changes in gusts or direction	Check observations and warnings before treating the forecast window as usable.

A gust gap alone cannot identify whether the cause is terrain, convection or a front. A local forecast discussion and observations add context that the hourly line does not. Our guide on gusts versus average wind covers the mechanism.

Direction and the spot

Wind is named for where it comes from, so a "northerly" blows from north to south. At a given beach that single fact decides whether the wind is cross-shore, onshore or offshore, and no amount of speed compensates for the wrong one. Read direction across the whole session window rather than at one moment — a change through the afternoon can alter the site’s exposure.

Reading the build

The most useful part of an hourly wind chart is its slope.

1. Find when the line crosses your minimum. That is the earliest sensible arrival, not the time you should already be on the water.
2. Find the plateau. The flat part is the session; the ramp is setup and the ramp down is packing up.
3. Check whether the drop is sharp or gradual. A sharp fall can have several causes; check the local forecast rather than diagnosing it from the slope alone.
4. Cross-check the rain bars. A wind spike near rain deserves attention, but an hourly chart cannot identify or rule out a squall. Check marine warnings before heading out.

What this does not replace

A forecast is a model of the atmosphere, not an observation of your beach. Local terrain, thermal effects and sea state all bend it, and nothing on a chart substitutes for looking at the water and at whatever live station your spot has. Use the timeline to decide whether to make the drive; use your eyes to decide whether to go out.

Sources and what changed

• RNLI: kitesurfing safety covers wind direction, training and equipment checks.
• NWS: marine weather messages explains official marine advisories and warnings. Use the equivalent local service outside the US.
• Checked 20 October 2026: removed universal gust ratios and kite-sizing advice. Numerical examples compare forecasts; they are not safe operating limits.