The park and the valley are at their best in late spring (May–June) and early autumn (September–October). Temperatures are mild, the reservoir is well stocked with trout, the cottonwoods are green in spring and golden in autumn, and the campground is busy but not overwhelmed.
Summer (July–August) is warm — daytime temperatures in the valley can reach the mid-30s Celsius — and the park fills with Utah families on weekends. Swimming and paddleboarding are popular, and the golf course is in good condition, but expect more noise and less solitude than the shoulder months offer.
Palisade State Park is open approximately April to October. Outside these months the park largely closes, the campground shuts and access may be limited; call ahead if you are visiting in April or late October. The valley itself is accessible year-round, and winter brings snow to the surrounding mountains, but there is little reason to stop unless you are passing through on US-89.