During the day of the accident, the pilot received 7 weather briefings which described marginal VFR conditions for his route of flight. At about 1730 CST, he departed Kansas City on a VFR flight plan to Farmington, MO. During the flight, he encountered adverse weather. At 1911 CST, the pilot transmitted that he was over the Farmington Regional Airport at 2800 ft in clouds. Two minutes later, he said he regained contact with the ground and requested conditions at Farmington. Farmington did not report the weather, but he was provided weather information at other locations. The pilot elected to proceed to St Louis, MO. Radio contact was lost while attempts were made to provide assistance. A witness heard the plane circling his house. He went outside and saw the plane before it disappeared momentarily and then come out of the clouds in a descent. The plane crashed on downward sloping, wooded terrain. A witness said the visibility was poor and it was misting.