September is the best month to visit almost any national park in the country and it is not close. The school holidays end, the summer crowds vanish in the first week, the high country stays open, and the light gets long and low. If you can only take one trip a year, take it in September.
1. Glacier National Park, Montana
The first half of September is the sweet spot: Going-to-the-Sun Road still open, vehicle reservations usually finished for the season, larches beginning to turn, and the trails suddenly quiet.
Services start closing from mid-month and the road can shut on any early snow. Go early in the month, not late.
Our 3 days itinerary: Best Day Hikes in Glacier National Park: 3-Day Weekend. Day by day, with where to sleep and what to book.
2. Yellowstone and Grand Teton, Wyoming
The elk rut runs through September and the bugling in the Tetons at dawn is one of the great wildlife experiences in the country. The summer traffic has gone and the aspens turn gold from the middle of the month.
Nights drop below freezing well before the days do. Pack for two seasons in one day.
Our 7 days itinerary: Yellowstone & Grand Teton: 7-Day Mountain West Road Trip. Day by day, with where to sleep and what to book.
3. Olympic National Park, Washington
September is the driest month on the peninsula, which in a rainforest matters more than the temperature. The high country at Hurricane Ridge stays open, the coast is walkable, and the rivers are low enough to ford.
Three ecosystems inside one park, and September is the only month all three are comfortable at once.
Our 3 days itinerary: Olympic Peninsula Loop: 3-Day Pacific Northwest Road Trip. Day by day, with where to sleep and what to book.
4. Maroon Bells, Colorado
The aspens around Maroon Lake turn in the last ten days of September and the Four Pass Loop through them is the best week of walking in Colorado. It is also the most photographed view in the state, so plan around the crowds rather than pretending they are not there.
Reserved parking and shuttles are required at Maroon Lake in season. Book that before anything else.
Our 3-4 days itinerary: Maroon Bells Four Passes Loop: Backpacking Guide. Day by day, with where to sleep and what to book.
5. Acadia National Park, Maine
September on Mount Desert Island is warm days, cold nights, and no cruise-ship crowds. The foliage does not really turn until early October, so September buys you the weather without the traffic.
The carriage roads are at their best now, and the Cadillac summit road reservation system quietens down after Labor Day.
Our 3 days itinerary: Acadia National Park 3-Day Itinerary: Best Hikes + Where to Stay. Day by day, with where to sleep and what to book.
6. Eastern Sierra, California
Bishop and Mammoth in late September have stable weather, cold clear nights and aspens turning in the canyons. The high passes are still open and the summer permit scramble is over.
Autumn colour in the Sierra is a two-week event and it moves with elevation. Start high and work down.
Our 10 days itinerary: Eastern Sierra 10-Day Loop: Mammoth Lakes Backpacking Trip. Day by day, with where to sleep and what to book.
More trips that work in September
- North Cascades Backpacking: A 4-Day Itinerary 4 Days · Washington
- Wind River Range Backpacking: A 7-Day Itinerary 7 Days · Wyoming
- Superior Hiking Trail: A 4-Day Minnesota Itinerary 4 Days · North Shore
- Presidential Traverse: A New Hampshire Weekend Itinerary 2–3 Days · New Hampshire
