Spring Green is essentially a summer destination. Taliesin tours run from May through October, the American Players Theatre season is June through September, and the House on the Rock is at its fullest from late March to early November. The juried arts fair on the last weekend in June is one of the biggest in the upper Midwest and draws large crowds, so book accommodation well ahead if you plan to attend.
July and August are warm and humid — the river floats and swimming holes are part of the appeal — while September and early October offer pleasant temperatures, smaller crowds, and the beginnings of fall colour on the surrounding hills. Winter is quiet; most attractions close or move to a reduced schedule.