Yellowstone National Park in September
Crowds and weather in September · NPS visitor counts 2022–2025 · NOAA 1991–2020 averages
September at a glance
Crowds: Peak — about 28,301 visitors a day, 89% of the July peak. September is the 9th quietest month of 12.
Weather: average high 65°F (18°C), low 30°F (-1°C); 1.7 in (43 mm) of precipitation on about 4 days, 1 in of snow.
Verdict: ○ Mild weather, busy.
Best balance at Yellowstone: May (55% of peak, high 55°F).
September visitors, year by year
| September | Recreation visits | Per day |
|---|---|---|
| 2022 | 567,587 | 18,920 |
| 2023 | 838,458 | 27,949 |
| 2024 | 852,435 | 28,415 |
| 2025 | 839,579 | 27,986 |
“Unusually low” marks a year when September's share of the annual total was less than half the other years' — usually a closure (storms, fire, a government shutdown) or a counting gap. The typical figure above uses the median share of 2022–2025, scaled to 2025's total.
September compared with the months around it
| Month | Crowds · visitors/day | High / low · precip. |
|---|---|---|
| August | Peak89% of peak · 28,329/day | 75° / 37°F1.4 in · 4 wet days |
| September | Peak89% of peak · 28,301/day | 65° / 30°F1.7 in · 4 wet days |
| October | Quiet33% of peak · 10,645/day | 50° / 22°F2.3 in · 6 wet days |
All 12 months at Yellowstone →
Other parks with mild weather and fewer people in September
- Shenandoah
47% of peak · high 78°F
- Crater Lake
55% of peak · high 63°F
- Mount Rainier
56% of peak · high 57°F
Months with few visitors can mean seasonal closures of roads, shuttles or campgrounds. Check current conditions on the official Yellowstone National Park website before you go.
Sources. Visitor counts: National Park Service, Visitor Use Statistics (recreation visits, final figures through 2025; typical months use 2022–2025). Weather: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (station OLD FAITHFUL, USC00486845, 7,352 ft / 2,241 m). Both are U.S. Government works in the public domain. How we calculate.
Park Months is an independent site and is not affiliated with the National Park Service or NOAA.