According to the pilot, while on approach to a private grass air strip he observed the midfield wind sock indicating light and variable winds. After a normal approach and touch down, during the landing roll he encountered a strong crosswind from the right. Subsequently, the airplane began to swerve and then entered a ground loop to the left. During the ground loop, the right wing impacted the runway and the airplane came to rest. The pilot reported that after he exited the airplane, he observed a quartering tailwind at 15 miles per hour. The pilot stated there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The right wing and elevator were substantially damaged in the accident. The reported winds at an airport 5 nautical miles away about the time of the accident were from a variable direction at 3 knots.