September is an excellent month at Mount Rainier — it ranks 3rd of the twelve here. Expect about 44% fewer visitors than July, the park's peak — 234,962 visits on average. Days run around 57°F by afternoon and 41°F at night, with 12.5 hours of daylight.
September against the park's best
| Month | Verdict | Avg. visits | vs. peak | High | Low | Snow | Daylight |
|---|---|---|---|---|---|---|---|
| September (this page) | Excellent | 234,962 | −44% | 57°F | 41°F | — | 12.5 h |
| May (best) | Excellent | 85,473 | −80% | 48°F | 33°F | — | 15 h |
| July (peak crowds) | Good | 420,918 | peak | 62°F | 44°F | — | 15.5 h |
Weather figures are for the Paradise area (5,400 ft) — the Rainier Paradise RS station. Visits are 2021–2025 averages; climate normals cover 1991–2020. Conditions vary across the park; check current status before you go.
Common questions
Is September a good time to visit Mount Rainier?
Yes — it is one of the best months of the year here. September ranks 3 of 12 at Mount Rainier on crowds, weather, daylight, and access together.
How crowded is Mount Rainier in September?
About 234,962 recreation visits on average — 44% below July, the park's peak.
How warm is Mount Rainier in September?
Average highs around 57°F and lows around 41°F at the Rainier Paradise RS station.
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