Sailing

Winds of Lake Geneva

Varied winds, thunderstorms and breezes sweep across Lake Geneva, which is located between the Alps and the Jura mountains. This Genevan air is well known to sailors and changes both over the seasons and throughout the day across the lake's surface area of some 580 km².

General winds

The Vent

A strong south-westerly to westerly wind, the Vent is generally seen in summer at speeds of between 35 and 70 km/h, accompanied by an area of low pressure. Heavy rain clouds over Geneva and the Jura region are also common.

The Bise

A north-easterly wind, the Bise is generally formed between a high-pressure area in the north and a low one in the Gulf of Genoa. Its strength varies between 15 and 90 km/h. It brings good weather, which is cold and dry, for three to ten days.

The Vaudaire

A strong south-easterly wind, the Vaudaire comes from the Rhone delta and buffers the Upper Lake and Large Lake of Geneva at over 50 km/h. It results from a difference in pressure between the northern and southern slopes of the Alps (an extension of the Foehn) or in summer from storms originating in the Jura that violently bounce back against the Alps.

The Vent blanc

This 'white wind' blows in summer when the weather is still very sunny. Mainly seen on the Small Lake, it can reach the Large Lake but only very rarely the Upper Lake. A hot, stable wind, it has speeds of about 25 km/h (7m/s).

The Joran

A northwesterly wind, often seen in spring. The Joran features strong gusts of more than 100 km/h that stablise at 50 km/h. When it blows, the temperature drops sharply.

Thunderstorms

The Bornan

A blustery wind that sweeps down the Genevan slopes of the Alps at more than 120 km/h. Its effects are mainly felt on the Large Lake. This stormy wind springs up very suddenly on extremely hot days.

The Môlan

A stormy wind on the Small Lake.

Daytime breezes

The Rebat

The Rebat appears at the hottest times of the day, often after the Bise or from open waters to the coast, in a westerly or northwesterly direction. Although gentle, it can reach speeds of over 20 km/h.

The Séchard

A light wind, it blows only on the Small and Large Lakes during the day.

Noctural breezes

Nocturnal breezes can reach speeds of 20 km/h. Funnelling up through valleys, where they pick up speed, they are seen in late afternoon. The more jagged the landscape, the greater the acceleration.

In different regions, these are called the: Jorasson, Morget, Bisoton, Dézaley, Jaman, Vauderon, Albrans, Birran, Molaine, Fraidieu.

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Winds of Lake Geneva

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