Early autumn · Weather & things to do
Yellowstone in September
Yellowstone cools off: highs slip to 60°F (16°C), from 71°F in August, with lows of 34°F (1°C) and about 2.0 in (52 mm) of rain.
At 86/100 for comfort (3rd of 12), it's one of the best months to visit.
- Avg high
- 60°F (16°C)
- Avg low
- 34°F (1°C)
- Rain
- 2.0 in (52 mm)
- Humidity
- 58%
- Cloud cover
- 48%
- Daylight
- ~12 h 17 min
- Comfort score
- 86/100 · Great
What September feels like
Days are mild at around 60°F (16°C): comfortable for walking all day, with a layer for the evening.
There's a big swing between day and night, about 15°C (26°F), so mornings and evenings feel much cooler than the afternoon.
About 2.0 in (52 mm) of rain falls in a typical year's September.
Plan around September
September is one of Yellowstone's best months on the climate data.
- Last of the best-scoring months: by October, the score drops to 50/100.
- Comfort slips from 96/100 in August to 86/100.
- 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 34°F
- Comfortable walking shoesmost picks involve some walking
What to do in Yellowstone in September
September is good outdoor weather here, so these picks lean toward the open air.
West Yellowstone
Montana gateway town at the West Entrance, where most snowcoach and guided snowmobile tours to Old Faithful begin.
Why now September scores 86/100 for comfort, good conditions for being outside.
Lamar Valley
Wide valley in northeast Yellowstone with bison, elk and the park's best chances of seeing wolves in winter.
Why now Highs near 60°F and 2.0 in of monthly rain make this an easy outdoor pick.
Grand Prismatic Spring
The largest hot spring in the United States, in Midway Geyser Basin; in winter its steam drifts over the Firehole River.
Why now One to do outside while the weather is on your side.
Grand Canyon of the Yellowstone
Yellow-walled canyon where the 308-foot Lower Falls builds a huge cone of ice in winter.
Nearby in September
- Yellowstone National Park in September~13 mi · highs 61°F, 2.0 in rain · similar daytime temperatures, about as wet
- Grand Teton National Park in September~57 mi · highs 65°F, 2.0 in rain · 3°C (5°F) warmer by day, about as wet
- Jackson in September~79 mi · highs 70°F, 1.8 in rain · 5°C (9°F) warmer by day, about as wet
- Salt Lake City in September~274 mi · highs 79°F, 1.5 in rain · 11°C (19°F) warmer by day, about as wet
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Yellowstone in September: quick answers
Is September a good time to visit Yellowstone?
Yes. On the climate data it's one of the best months, scoring 86/100. Expect highs of 60°F (16°C) and 2.0 in (52 mm) of rain. Our Grand Teton, Jackson & Yellowstone route recommends Mid-Dec – Mar, so September is outside its suggested window.
How cold is Yellowstone in September?
Average highs are 60°F (16°C) and average lows 34°F (1°C), making it the 4th-warmest month by daytime highs.
Does it rain a lot in Yellowstone in September?
Not much: about 2.0 in (52 mm) of rain falls across September on average, the 3rd-driest month of the year. The annual total is about 32.8 in (834 mm).
What should I pack for Yellowstone in September?
Bring a warm layer for evenings (lows near 34°F) and comfortable walking shoes (most picks involve some walking).
More on Yellowstone
Planning Yellowstone in September?
Share this September plan with your group, poll everyone on dates and keep the packing list in one place.