mistral, cold and dry strong wind in southern France that blows down from the north along the lower Rhône River valley toward the Mediterranean Sea. It may blow continuously for several days at a time, with velocities that average about 74 km (about 45 miles) per hour, and reach to a height of 2 to 3 km (about 1.2 to 1.9 miles). It is strongest and most frequent in winter, and it sometimes causes considerable damage to crops. The velocity of the wind is intensified as it blows down from the highlands to the coast and by the “jet effect” that results as it is funneled through the narrow Rhône valley. As the winds move out over the Rhône delta, they can reach velocities of 130 km (about 80 miles) per hour.