The solo student pilot reported that, during approach to land, the airplane encountered turbulence and he felt that the wind was from "more than one direction," and on final, he decided to use only two notches of flaps. He landed the airplane "slightly sideways" and the airplane veered right. The airplane exited the runway to the right toward a "small hump in the grass." He was afraid of tipping the airplane with too much left rudder, so he delayed left rudder input until on top of the "hump." He added left rudder and returned to the runway. The chief pilot reported that the student "lost control" and struck a runway sign with the right wing and a runway light with the left flap. The airplane sustained substantial damage to the right wing. The chief pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The airport's automated weather observation station reported that, about 5 minutes before the accident, the wind was from 230° at 10 knots, gusting 16 knots. The student landed the airplane on runway 18.