The pilot said that the pre takeoff weather briefing contained a forecast for winds well within the normal range of the balloon's normal operating envelope. The pilot said after about 45 minutes of flight, his ground crew reported an increase in the surface winds to about eight knots. The pilot observed that as he prepared for an approach he noted that several balloons on the ground were laying over. The pilot said he selected a large field and briefed his passengers on a high wind landing. At a point about eight feet above the ground, the winds increased to 12 knots with higher gusts. The pilot reported that he was unable to overcome the wind effects and the balloon touched down hard. The pilot stated that the injured passenger's foot was placed in a recessed area of the basket floor which did not allow for any lateral movement. On ground touchdown, the passenger sustained a dislocation fracture of that ankle.