1. Yosemite National Park, CA
In the fall, busy Yosemite sees a drop in attendance—and a drop in water levels, which affects the waterfalls. But the best part is the drop in temperature, which makes hiking more enjoyable. In September, the average temperature is a decent, last-vestige-of-summer 83 degrees, although parts of the park like Tuolumne Meadows can be significantly colder, even by 20 degrees!
Where to stay: With an on-site spa, a year-round heated pool, and close proximity to the park's entrance, Rush Creek Lodge is a perfect base for exploring Yosemite.