The pilot reported that during the final leg of the approach, the airplane was above the intended approach path and speed. Over the threshold of the runway, the airplane encountered a gust of wind. The pilot announced his intention on the common traffic advisory frequency that he was going to perform a go-around maneuver. He was unable to perform the maneuver prior to the hard landing, he then proceeded to overrun the runway, and nosed over, which resulted in substantial damage to the left wing. The pilot reported there were no mechanical malfunctions or failures with the airplane that would have precluded normal operations. The recorded wind at the airport about the time of the accident was variable at 4 knots and for the hour before and an hour after the accident the wind was recorded as calm.