Canyonlands is a wilderness of countless canyons and fantastically formed buttes carved by the Colorado River and its tributaries. The rivers divide the park into four districts: Island in the Sky, The Needles, The Maze, and the rivers themselves. These areas share a primitive desert atmosphere, but each offers different opportunities for sightseeing and adventure. Canyonlands is part of the Colorado Plateau, a high desert region with wide temperature fluctuations, sometimes more than 40 degrees in a single day. The most temperate and popular seasons are spring, from April to May, and fall, from mid-September to October, when daytime highs average 60 to 80 F and lows average 30 to 50 F. Summer temperatures often exceed 100 F, making strenuous exercise difficult. Winters are cold, with highs averaging 30 to 50 F and lows averaging 0 to 20 F.