The big Rockies loop — geysers, the Tetons skyline, then north to Going-to-the-Sun Road before the passes close. Early-to-mid July is peak, warm, unpredictable mountain summer: Yellowstone and Grand Teton lower elevations run highs in the 70s–80s with overnight lows in the 40s, while Glacier runs similar but is prone to sharp, sudden afternoon thunderstorms with lightning — plan hikes for morning starts. High-elevation trails at Glacier (Highline, Logan Pass area) can still have lingering snowfields into early July, so check current conditions before committing to those routes. Pack layers and rain gear regardless of the forecast; a sunny 75°F morning can turn to hail by mid-afternoon at these elevations.
The big Rockies loop — geysers, the Tetons skyline, then north to Going-to-the-Sun Road before the passes close. Early-to-mid July is peak, warm, unpredictable mountain summer: Yellowstone and Grand Teton lower elevations run highs in the 70s–80s with overnight lows in the 40s, while Glacier runs similar but is prone to sharp, sudden afternoon thunderstorms with lightning — plan hikes for morning starts. High-elevation trails at Glacier (Highline, Logan Pass area) can still have lingering snowfields into early July, so check current conditions before committing to those routes. Pack layers and rain gear regardless of the forecast; a sunny 75°F morning can turn to hail by mid-afternoon at these elevations.