Wind for Paragliding: Surface Wind, Gusts, Valley Wind and Foehn
How much wind is too much? Surface wind, gusts, wind aloft, valley winds and foehn explained clearly — with rules of thumb for launch, flight and landing.
Paragliders fly at around 35–40 km/h trim speed. Any wind that gets close to that eats up your margin. That’s why wind is the first question in any flight planning — before thermals.
Surface wind and gusts
Surface wind is the mean wind at 10 m. Gusts are the peaks within it. What matters is not just the peak but the gap: if gusts are far above the mean, the air is turbulent — even when the mean wind looks harmless. A difference of more than about 15 km/h is a clear warning sign.
By default, the thermal map rates launches as possible up to about 29 km/h mean wind and 40 km/h gusts, and slightly above that as marginal. Those are upper limits for experienced pilots, not a recommendation. For newer and leisure pilots the personal limit is much lower — often 15–20 km/h.
Wind direction and launch sector
Every launch is approved for certain directions. On the map, launch sectors show these as fans and wind arrows show the forecast wind. If the arrow fits in the fan, the direction fits. Cross-wind is unpleasant on launch and often turbulent behind terrain edges.
Wind aloft: the wind you don’t feel at launch
Launch can be almost calm while it blows 40 km/h at ridge height — typical with westerly flow. The result: torn-up thermals, lee turbulence behind ridges and a headwind you can barely penetrate. So check the barbs above launch in the meteogram, not just the surface wind.
Valley wind: the afternoon wind in the mountains
On sunny days, air flows from the lowlands into the alpine valleys and up the slopes. This valley wind starts in the late morning and can get strong in big valleys by the afternoon. It’s not a model error — it’s too small-scale for most models. For landing, that means: land early or pick a landing field you approach into the valley wind.
Foehn: not a flying day
Foehn happens when air flows over the main alpine ridge and drops down the lee side as a warm, dry, gusty downslope wind. Signs:
- strong southerly (south foehn) or northerly (north foehn) wind aloft
- a wall of cloud over the main ridge (the “foehn wall”), lens-shaped lenticular clouds
- unusually clear visibility and warm, dry air
- a large pressure difference between the north and south side of the Alps
Foehn can look deceptively calm at a single launch and break through minutes later. With a foehn situation: don’t fly.
Lee and rotors
Behind any obstacle — ridge, summit, tree line, building — wind creates a turbulent zone. Rule of thumb: the lee reaches roughly five to ten times the obstacle’s height downwind. Before flying, work out where the lee is for today’s wind direction, and whether your route or landing approach passes through it.