The pilot reported that during the landing flare he encountered "wind shear" and crosswind conditions. About 10 feet above the runway, the airplane ballooned and the nose rotated 30 degrees to the left. He added full power to go-around, but the airplane drifted to the left of the runway and the left wing impacted a tree. Subsequently, the airplane spun around 180 degrees and came to rest in grass to the left of the runway. The fuselage and left wing sustained substantial damage. The pilot reported that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. A routine aviation weather report 8 nautical miles southwest of the airport reported the wind at 020 degrees true at 13 knots gusting to 17 knots, and clear skies. The landing runway heading was 350 degrees magnetic, which resulted in a 10 knot crosswind component.