Grand Teton National Park
The area is known for long, cold winters. The first heavy snows fall by November 1 and continue through March, with snow and frost possible in any month. Summer days are usually in the 70s and 80s with cool nights in the 40s, and summer thunderstorms are common. Mild to cool temperatures are normal through September and October. Raingear is recommended during spring, summer, and fall. Sub-zero temperatures are common throughout winter and demand multi-layered clothing, hats, mittens, and cold weather boots.
The average weather ranges described below are at valley elevations. Temperatures are cooler in the mountains, with more moisture. Be aware that mountain weather changes quickly. Check the weather forecast before starting your trip.
Spring: Late April to June, mild days and cold nights intersperse with rain and occasional snow. Valley lakes usually thaw by late May. Snow level may remain just above valley elevation until mid-June. Average ranges: temperature 22 to 71 degrees, snow 0-11", rainfall 1-3".
Summer: July to August, warm days and cool nights prevail, with afternoon thunder showers common. Snow level gradually retreats, with mountain divides free of snow by August. Average ranges: temperature 39- 81 degrees, rainfall 1-2".
Fall: September to November, sunny days and cold nights alternate with rain and snowstorms. Snow becomes persistent by late fall. Average range: temperature 15-69 degrees, snow 1- 25", rainfall 1-2".
Winter: Late November to April, snow blankets Jackson Hole with accumulations of ten feet common in the mountains and two to five feet in the valley. Blizzards are common with occasional sunny days and frigid nights between storms. Average range: temperature 2-31 degrees, extreme -43 degrees, snow 33-49".
Details mentioned in this article were accurate at the time of publication