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.