Neal Herbert | Yellowstone National Park
Spring and autumn offer quite warm and mild weather, less crowds, and beautiful blooming or fall foliage. Spring is a perfect time for watching baby animals! Early fall is ideal for climbing, biking, and trekking due to the pleasant and not hot weather conditions.
There is much less traffic in the park, so it's easier to get around. On the other hand, the park can meet you with rain and even snowfall as the weather is really unstable during these seasons. Some roads can be closed due to the snow melting in spring.
