Yellowstone National Park in September
In September, Yellowstone National Park averages a high of 61°F and a low of 30°F, with 1.6 inches of precipitation (rain plus melted snow). About 843,000 people visit, the 4th busiest of 12 (very busy). Days are 12 hours 28 minutes long.
- Quiet
- Moderate
- Busy
- Very busy
- Few or no visits (may be closed)
- Best months
- High / low
- 61° / 30°F
- Precipitation
- 1.6in
- Snow
- –in
- Daylight
- 12h 28m
- Visitors
- 843,000
- Crowds
- Very busy
September is one of the best months to visit: mild weather with very busy crowds.
Higher or lower in the park, expect a different picture: Gardiner, MT at 5,275 ft averages a September high of 76°F and a low of 44°F.
Weather 1991–2020 averages at Yellowstone Lake, WY, 4.3 miles from the park's center, 7,835 ft. Second station lower down: Gardiner, MT, 5,275 ft, 32.7 miles. Visitors National Park Service recreation visits, average of 2023–2025. Updated .
Other parks in September
| Park | High / low °F | Crowds | Weather |
|---|---|---|---|
| John D. Rockefeller, Jr., Memorial Parkway | 66° / 28° | Busy | Mild |
| Grand Teton National Park | 66° / 34° | Busy | Mild |
| Glacier National Park | 68° / 41° | Busy | Mild |
| Mount Rushmore National Memorial | 69° / 50° | Moderate | Mild |
| Wind Cave National Park | 76° / 46° | Busy | Mild |
Closures, reservations and alerts: Yellowstone National Park on nps.gov
All twelve months at Yellowstone · National parks to visit in September