Early autumn · Weather & things to do
Grand Teton National Park in September
Grand Teton National Park cools off: highs slip to 65°F (19°C), from 76°F in August, with lows of 39°F (4°C) and about 2.0 in (50 mm) of rain.
At 94/100 for comfort (3rd of 12), it's one of the best months to visit.
- Avg high
- 65°F (19°C)
- Avg low
- 39°F (4°C)
- Rain
- 2.0 in (50 mm)
- Humidity
- 56%
- Cloud cover
- 44%
- Daylight
- ~12 h 17 min
- Comfort score
- 94/100 · Great
What September feels like
Expect mild afternoons around 65°F (19°C), good for long walks.
There's a big swing between day and night, about 14°C (26°F), so mornings and evenings feel much cooler than the afternoon.
About 2.0 in (50 mm) of rain falls in a typical year's September.
Plan around September
September is one of Grand Teton National Park's best months on the climate data.
- Last of the best-scoring months: by October, the score drops to 60/100.
- Comfort holds steady from August (96 → 94/100).
- September sits inside the Jun – Sep window our Glacier to Yellowstone route recommends.
- Our Grand Teton, Jackson & Yellowstone route recommends Mid-Dec – Mar, so September falls outside its suggested window.
What to pack for September
- A warm layer for eveningslows near 39°F
- Comfortable walking shoesmost picks involve some walking
What to do in Grand Teton National Park in September
September is good outdoor weather here, so these picks lean toward the open air.
Grand Teton
At 13,775 feet, the highest peak of the Teton Range, rising about 7,000 feet straight from the valley floor.
Why now September scores 94/100 for comfort, good conditions for being outside.
Teton Park Road winter trail
The park road from Taggart Lake Trailhead to Signal Mountain closes to cars in winter and is groomed for skiing and snowshoeing.
Why now Highs near 65°F and 2.0 in of monthly rain make this an easy outdoor pick.
Mural Room
Jackson Lake Lodge's main dining room with 60-foot windows facing the range.
Why now One to do outside while the weather is on your side.
Mormon Row
Row of 1890s homesteads east of Blacktail Butte, including the much-photographed Moulton barns facing the Tetons.
Signal Mountain Summit Road
Winding road to an overlook above Jackson Lake and the whole range.
Million Dollar Cowboy Bar
Jackson's town-square saloon since 1937, with saddle barstools and live country music.
Nearby in September
- Jackson in September~22 mi · highs 70°F, 1.8 in rain · 2°C (4°F) warmer by day, about as wet
- Yellowstone National Park in September~44 mi · highs 61°F, 2.0 in rain · 3°C (5°F) cooler by day, about as wet
- Yellowstone in September~57 mi · highs 60°F, 2.0 in rain · 3°C (5°F) cooler by day, about as wet
- Salt Lake City in September~218 mi · highs 79°F, 1.5 in rain · 8°C (14°F) warmer by day, about as wet
NASA POWER 2001–2025 monthly averages on a ~50 km grid, temperatures adjusted from the grid cell's ~2,462 m to Grand Teton National Park's ~2,122 m elevation (standard lapse rate). Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Grand Teton National Park in September: quick answers
Is September a good time to visit Grand Teton National Park?
Yes. On the climate data it's one of the best months, scoring 94/100. Expect highs of 65°F (19°C) and 2.0 in (50 mm) of rain. September is inside the Jun – Sep window our Glacier to Yellowstone route recommends.
How hot is Grand Teton National Park in September?
Average highs are 65°F (19°C) and average lows 39°F (4°C), making it the 4th-warmest month by daytime highs.
Does it rain a lot in Grand Teton National Park in September?
Not much: about 2.0 in (50 mm) of rain falls across September on average, the 3rd-driest month of the year. The annual total is about 30.9 in (785 mm).
What should I pack for Grand Teton National Park in September?
Bring a warm layer for evenings (lows near 39°F) and comfortable walking shoes (most picks involve some walking).
More on Grand Teton National Park
Routes in season in September
- Glacier to Yellowstone Jun – Sep
Planning Grand Teton National Park in September?
Plan it together in TripsCircle: one itinerary, one shared packing list and costs split as you go.