When to Go

High Season (May–Aug)

  • Summer temperatures can soar above 100°F (38°C) and park traffic is at maximum capacity.
  • July and August afternoon thunderstorms bring relief, but also create flash floods.

Shoulder (Mar & Apr, Sep–Nov)

  • Spring is pleasant but unpredictable. At higher elevations, snow can linger into May or June.
  • Fall is ideal: September is still hot, but days are clear, rivers remain warm and leaves begin to change.

Low Season (Dec–Feb)

  • Businesses have shorter hours or close altogether, but the peace and quiet make it a great time to visit.
  • Winters are generally mild at low elevations; expect snow and road closures at higher elevations.