Mount Rainier National Park in September
In September, Mount Rainier National Park averages a high of 57°F and a low of 41°F, with 4.4 inches of precipitation (rain plus melted snow). About 207,000 people visit, the 4th busiest of 12 (moderate). Days are 12 hours 30 minutes long.
- Quiet
- Moderate
- Busy
- Very busy
- Few or no visits (may be closed)
- Best months
- High / low
- 57° / 41°F
- Precipitation
- 4.4in
- Snow
- –in
- Daylight
- 12h 30m
- Visitors
- 207,000
- Crowds
- Moderate
September is one of the best months to visit: mild weather with moderate crowds.
Higher or lower in the park, expect a different picture: Longmire Rainier Nps, WA at 2,762 ft averages a September high of 69°F and a low of 42°F.
Weather 1991–2020 averages at Rainier Paradise RS, WA, 5.1 miles from the park's center, 5,427 ft. Second station lower down: Longmire Rainier Nps, WA, 2,762 ft, 8.8 miles. Visitors National Park Service recreation visits, average of 2023–2025. Updated .
Other parks in September
| Park | High / low °F | Crowds | Weather |
|---|---|---|---|
| Fort Vancouver National Historic Site | 76° / 52° | Moderate | Mild |
| Olympic National Park | 68° / 48° | Very busy | Mild |
| Ross Lake National Recreation Area | 70° / 50° | Busy | Mild |
| North Cascades National Park | 71° / 50° | Busy | Mild |
| Lake Roosevelt National Recreation Area | 73° / 40° | Moderate | Mild |
Closures, reservations and alerts: Mount Rainier National Park on nps.gov
All twelve months at Mount Rainier · National parks to visit in September