Wetterhall was a vigorous sportsman and an experienced competition organizer. As a young man, he belonged to the elite of Swedish modern pentathlon and became military pistol champion in 1958. Wetterhall was also at an old age a good skier and marksman. He was used to lead major skiing competitions in cross-country skiing; including the Swedish Cross-Country Skiing Championships in Kiruna in 1948 and the FIS Nordic World Ski Championships 1954 and the FIS Nordic World Ski Championships 1974. At the age of 68, he personally led by hiking and skiing, the construction of tracks for the latter competition. As a board member of the Ski Alliance ("Skidalliansen") and chairman of Dalarna Ski Association, Wetterhall seemed to that the Swedish Ski Games in Falun became a reality and he led the tracks construction of the Ski Games as long as he could.