Fall in Denali National Park – Autumn Colors and Mt. Denali View The best time to visit Denali is in the fall Why September is Denali's Best-Kept Secret. When most travelers think of visiting Denali National Park, they picture summer—long days of endless sunlight, wildflowers blooming in alpine meadows, and wildlife roaming freely across the tundra. But ask any local or returning visitor in the know, and they’ll tell you the truth: September is Denali’s best-kept secret. Th