The weather in Grand Teton National Park is unpredictable and can be severe. Always bring rain gear and warmer clothes even in summer. Expect cool alpine nights even if the days are very warm. Storms can hit fast and hard, so always be prepared.

Avg max high/low temp:

January: high 25.7, low 1.2
July: high 79.8, low 41.2
September: high 68.9, low 32.2