Yellowstone · September
Yellowstone in September
September is a busy time to visit Yellowstone — quieter than August, busier than October.
Expect heavy crowds (7/10), highs near 68°F, about 12.5 hours of daylight, and 2 seasonal closures in effect.
Crowd score
How busy it gets
Approaching peak season — expect full lots by mid-morning and busy overlooks.
About 63% of this park's busiest month.
Source: NPS Visitor Use Statistics, 2023–2025
Data: NPS visitation 2023–2025 · crowd scores computed Oct 2026 · alerts checked Oct 18, 2026. How this is calculated →
Computed from federal data · Methodology by Sharon Ben-Moshe
Visitation
Typical September visits vs. the year
September draws about 14% of Yellowstone’s yearly visitors.
Typical monthly recreation visits, averaged over the most recent three full years.
Source: NPS Visitor Use Statistics, 2023–2025
Weather
September weather
- Avg high
- 68°F
- Avg low
- 37°F
- Precipitation
- 1.4"
- Sunrise
- 6:01 AM
- Sunset
- 6:32 PM
- Daylight
- 12.5h
Source: NOAA 1991–2020 climate normals, Yellowstone (Lake Yellowstone)
What's open
Yellowstone in September: access
Open 24 hours in season; most roads close to cars early Nov to late Apr
Seasonal closures may apply:
- Park Closure
Biscuit Basin Closed Due to Hydrothermal Explosion
The parking lot, boardwalk, and Firehole River at Biscuit Basin, located north of Old Faithful, is closed to all travel until further notice due to the possibility of another event at the site of a hydrothermal explosion that occurred July 23, 2024.
Details on nps.gov → - Road Closure
Seasonal road closures in effect
Most park roads are closed to regular vehicles between early November and late April. Check current road status before traveling.
Details on nps.gov →
Source: NPS Data API
Conditions
Current alerts
- Information
Vehicle Entrance Reservation Not Needed
Although an entrance pass is required to enter Yellowstone National Park, vehicle reservations are not needed. You are encouraged to purchase an entrance pass before arriving, but you may also purchase passes at any entrance station upon arrival.
Details on nps.gov → - Information
Traffic Delays - Gardner River High Bridge
Expect a single lane of traffic with up to 15-minute delays, 24 hours a day, seven days a week, from April 1 through late October 2026. Oversized/overweight vehicles (8'6"+ wide, 75'+ long, 80,000 lbs+ gross vehicle weight) will not be able to cross the bridge during this time.
Details on nps.gov → - Caution
Stay Away From Bull Elk
Bull elk are fast and unpredictable this time of year and can seriously injure people. If an elk charges, run. In addition to staying at least 25 yards (23 m) away from elk and bison, always stay at least 100 yards (91 m) away from bears and wolves.
Details on nps.gov →
Source: NPS Data API
Context
Yellowstone crowds across the year
Alternatives
Quieter nearby in September
FAQ
Yellowstone in September
How busy is Yellowstone in September?
September rates 7/10 for crowds (Busy) at Yellowstone National Park — about 63% of its busiest month. Typical recreation visits: 660,153.
What is the weather like at Yellowstone in September?
In September, Yellowstone averages a high of 68°F and a low of 37°F, with about 1.4 inches of precipitation.
How much does it cost to visit Yellowstone?
Entrance to Yellowstone costs $35 ($35 per private vehicle, valid 7 days).
When is Yellowstone least crowded?
Yellowstone is quietest in January and February. If your dates are flexible, those months bring the thinnest crowds of the year.
How many hours of daylight does Yellowstone get in September?
In mid-September, Yellowstone gets about 12.5 hours of daylight, with sunrise around 6:01 AM and sunset around 6:32 PM.