During spring and fall, the daytime highs average 60 to 80 F and lows average 20 to 50 F. Crowds are largest and campsites and backcountry permits are most difficult to obtain during holiday weekends such as Easter and spring break. Summer temperatures approach 100 F, and discourage crowds and tend to make strenuous exercise difficult.
Most precipitation falls in late summer and early autumn thunderstorms.
Though large snowfalls are uncommon in the park, even small amounts of snow or ice can make trails and roads impassible.