About an hour prior to the flight the pilot checked the surface observation report for the nearest airport, which was about 5 miles to the northeast. He stated that it indicated an indefinite ceiling of 200 feet and visibility of 3 miles with fog and ground fog. An aviation routine weather report (METAR) for the same airport was issued at the approximate time of the accident and reported, in part, winds from 130 degrees at 5 knots, visibility of 1 3/4 miles with mist, and skies with a 200-foot indefinite ceiling. The pilot stated that the visibility was good on the ground. As the airplane took off and climbed, he realized that the visibility went to zero. He turned around, attempting to get back to the airport, and he descended to get low enough under the fog to see the airport. There were trees on the east side of the airport, and he tried to stay above them while looking for the runway. He was on left downwind for runway 14 and turning base when the right wing hit a branch and the airplane subsequently impacted the ground. The right wing and empennage sustained substantial damage. The pilot reported no mechanical problems with the airplane or engine.