What will be the weather like in Yellowstone National Park?
April-May: Spring weather is pretty unpredictable in the park it can as low as 25°F and as high as 60°F.
June-August: Is the peak season and temperature the best this time of the season. Temperature can be as high as 80°F and even during summer, the temperature at night can fall to 30°F.
September-November: The temperatures remain mild during this season between 30°F to 60°F. Also suggested one of the best times to visit the park to avoid the crowd and you get more chances of viewing wildlife.