When to Go
Triple-digit temperatures are not uncommon in summer; luckily this means fewer crowds, especially on weekdays. Spring, particularly March and April, is the most popular season—a prime time to view spectacular displays of lupine, poppies, and other wildflowers. October through December is a great time to visit if you want to enjoy cooler temperatures and smaller crowds. Winters are cold by California standards, but this is an opportune time to hike, especially the High Peaks, where most of the trails are in the sun. Just keep in mind that temperatures in the deeply shaded areas such as the Balconies Trail can reach below freezing.
Note that Bear Gulch Cave is hugely popular but also home to a large colony of Townsend's big-eared bats. This protected species raises its young in late spring and summer, so the cave is closed from about mid-May to mid-July. Check the park website for the latest information on closures.