Everyone knows the day: the app shows 20 knots, you drive two hours, and the water at the spot is mirror-flat. Or the other way round – "only" 14 knots forecast, and it's firing. A forecast rarely lies, but it's often misread. Read a few values together instead of in isolation and you'll skip the wasted trips. Here are the figures that matter, in the order I check them myself.
1. Wind direction – more important than strength
Direction decides whether a spot works at all and whether it's safe. Onshore pushes you back to the beach – the safest case for beginners. Offshore drives you out to the open sea – a no-go without support and experience. Side-shore and side-onshore are the sweet spot for most disciplines. Every spot has its preferred direction; the same 20 knots is a dream day from the west and useless from the east. That's exactly why we list the best wind direction on every spot page.
2. Read gusts, not the average
Most people only look at the mean wind speed. The more honest value is the gust. When mean and gust sit close together – say 18 to 21 knots – the wind is stable and pleasant to ride. When they diverge – 14 mean, 28 gust – it gets rough, your gear is overwhelmed and kite choice becomes a gamble. Rule of thumb: the bigger the gap between mean and gust, the gustier and less pleasant it is.
3. Knots, km/h and the Beaufort scale
Surfers think in knots. One knot is about 1.85 km/h, so roughly knots times two for km/h. To put it in context: 12 to 15 knots is light wind (big kite), 16 to 22 is the comfort zone for most, and from 25 it gets sporty and you reach for the small kite. Don't be fooled by km/h figures in weather apps – 40 km/h sounds like a lot but is only about 21 knots.
4. Thermals – the wind no low pressure makes
At many Mediterranean and island spots the usable wind doesn't come from a low-pressure system but from the sun. Land heats up, warm air rises, cooler sea air flows in – that's the thermal sea breeze. It typically builds in the late morning, peaks in the afternoon and dies in the evening. Spots like Tarifa's Poniente or the Greek Meltemi areas live off it. A cloudless, hot day with a weak gradient wind is often the best thermal recipe.
5. Compare several models
No weather model is always right. When two independent models agree on the same day, the forecast is solid. When they diverge sharply, the situation is uncertain – plan flexibly and check again in the morning. The closer the date, the more reliable; anything beyond three or four days is a tendency rather than a promise.
Quick pre-session checklist
Is the direction right for my spot? How big is the gap between mean and gust? Does the strength match my skill and gear? Is it thermally driven – so only expected in the afternoon? Do the models agree? Five questions, two minutes, a lot less frustration at the water.
Frequently asked questions about wind forecasts
What do gusts mean in a wind forecast?
The gust is the short-term peak speed; the mean is the sustained wind strength. A big gap between them means gusty, unsteady wind; when they sit close together, it's even and easy to ride.
How many knots are good for kiting or windsurfing?
For most riders the comfort zone is between 15 and 22 knots. With a big kite you can get going from around 12 knots; from 25 knots you'll need smaller gear.
What's the difference between onshore and offshore?
Onshore blows from sea to land and pushes you back to the beach – safe for beginners. Offshore blows from land out to sea and is dangerous without experience and support.
How reliable is a wind forecast?
Quite reliable for the next one to two days, especially when several models agree. From about three to four days out the accuracy drops noticeably – then the forecast shows the trend rather than the exact strength.