Mount Rainier in September: Crowds, Weather & What to Pack
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September is one of the best months of the year to visit Mount Rainier National Park: crowds run 56% of the July peak (234,962 average visits). Weather: highs average 57°F and lows 41°F, with 4.4″ of precipitation and 12.6 hours of daylight. Computed from NPS and NOAA data.
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Bring for Mount Rainier in September
- Warm mid-layer (fleece or light puffy)See it on AmazonWhy: mornings average 41°F.
- Rain shell + pack coverSee it on AmazonWhy: 4.4″ of precipitation is normal this month.
- Waterproof bootsSee it on AmazonWhy: 4.4″ of precipitation is normal this month.
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Mount Rainier in September: what the park service says
September is the end of the Sunrise season at Mount Rainier: the park service says the Sunrise Visitor Center is generally open from July through mid-September. After that, the winter pattern sets in, with vehicle access only from the Nisqually Entrance and the Henry M. Jackson Memorial Visitor Center at Paradise moving to weekend and holiday hours from October 29 (10 a.m. to 3:30 p.m., conditions permitting, closed Monday to Friday). If you want to see the Sunrise side with its visitor center open, aim for early September and check the park road status page before you set out.
Source: NPS, checked 2026-11-05.
Crowds in September
Mount Rainier averages 234,962 recreation visits in September — 56% of what July, the peak month, draws. Trailheads and parking fill accordingly.
Weather & daylight
Days are cool (highs average 57°F), and mornings are chilly (lows average 41°F). This is one of the wetter months (4.4″ of precipitation on average). Mid-month daylight runs 12.6 hours.
NOAA 1991–2020 monthly normals, station RAINIER PARADISE RS, WA US (4 mi from park coordinates, 5,427 ft elevation) — conditions vary inside the park, especially with elevation. Daylight computed for the 15th of September.
What to pack for Mount Rainier in September
Computed from the month's weather normals above — not a generic list.
- Warm mid-layer (fleece or light puffy) — mornings average 41°F
- Rain shell + pack cover — 4.4″ of precipitation is normal this month
- Waterproof boots — plus navigation and a basic first-aid kit — 4.4″ of precipitation is normal this month
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Also at their best in September
Other parks whose computed September verdict is a best window — same NPS × NOAA formula:
- Wrangell–St. Elias in September — 25% of peak crowds, highs 56°F, score 84/100
- Guadalupe Mountains in September — 35% of peak crowds, highs 80°F, score 81/100
- Gateway Arch in September — 29% of peak crowds, highs 81°F, score 80/100
- Isle Royale in September — 39% of peak crowds, highs 65°F, score 79/100
Common questions
Is Mount Rainier crowded in September?
Moderately: September runs 56% of the July peak, averaging 234,962 visits (NPS, 2021–2025). See every month at Mount Rainier.
What is the weather like in Mount Rainier in September?
Average highs of 57°F, lows of 41°F, 4.4″ of precipitation (NOAA 1991–2020 normals, RAINIER PARADISE RS, WA US station). Compare it with other national parks in September.
What should I pack for Mount Rainier in September?
Warm mid-layer (fleece or light puffy); Rain shell + pack cover; Waterproof boots — plus navigation and a basic first-aid kit — the full weather-computed list is on this page. Going in October instead? Mount Rainier in October has its own list.
See also: the best national parks to visit in September · Last verified 2026-09-24